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Staff profile

Dr Andrew Copas

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Name: Andrew Copas Email: a.copas@ucl.ac.uk
Title: Dr Tel:
Department: Infection & Population Health Fax:
Position: Reader in Statistics Address: , , ,
Research Domain: Global Health, Infection, Immunology & Inflammation, Personalised Medicine, Populations & Lifelong Health Web Page:  

Profile

Research Description

Andrew's expertise in in medical statistics and he pursues research both in the methodology of that field, and its application to research in infectious disease epidemiology. He has considerable experience of working collaboratively with scientific colleagues on a range of study designs from lab research through to individual and cluster randomized clinical trials, epidemiological studies and surveys. Much of this research has been within the sexual health field, and Andrew heads a small statistical team at the UCL Centre for Sexual Health Research. He collaborates with researchers at the UCL Institutes for Women’s Health and Global Health, and researchers outside UCL. He is co-investigator for several ongoing and completed funded studies. He also pursues a programme of methodological research, which includes methods of analysis when some data are missing, the design and analysis of cluster randomised trials, methods for meta analysis, and the analysis of longitudinal data.


Research Activities

Education Description

UCL Collaborators

External Collaborators

Publications

    2014

    • Prah P, Copas AJ, Mercer CH, Nardone A, Johnson AM (2014). Patterns of sexual mixing with respect to social, health and sexual characteristics among heterosexual couples in England: analyses of probability sample survey data.. Epidemiol Infect, , 1 - 11. doi:10.1017/S0950268814002155
    • Hayward AC, Fragaszy EB, Copas A, Harvey G, Kovar J, Lim MSC, Millett ERC, Tabassum F, Wurie FB, Johnson AM, Nazareth I, Edmunds WJ, Bermingham A, Zambon M, Pebody R, Watson JM, Wang L, Goonetilleke N, McMichael A, Ferguson N, Nguyen-Van-Tam JS (2014). Comparative community burden and severity of seasonal and pandemic influenza: Results of the Flu Watch cohort study. The Lancet Respiratory Medicine, 2(6), 445 - 454. doi:10.1016/S2213-2600(14)70034-7
    • Miltz A, Price H, Shahmanesh M, Copas A, Gilson R (2014). Systematic Review and Meta-Analysis of L1-VLP-Based Human Papillomavirus Vaccine Efficacy against Anogenital Pre-Cancer in Women with Evidence of Prior HPV Exposure.. PLoS One, 9(3), e90348 - . doi:10.1371/journal.pone.0090348
    • Ewings FM, Ford D, Walker AS, Carpenter J, Copas A (2014). Optimal CD4 Count for Initiating HIV Treatment: Impact of CD4 Observation Frequency and Grace Periods, and Performance of Dynamic Marginal Structural Models.. Epidemiology, 25(2), 194 - 202. doi:10.1097/EDE.0000000000000043
    • Simmons R, Semenenko I, Tolpina M, Tereschenko R, Kotlik L, Zasyptka L, Murphy G, Mckinney E, Copas A, Malyuta R, Porter K (2014). High Percentage of Recent HIV Infection Leading to Onward Transmission in Odessa, Ukraine Associated with Young Adults. AIDS and Behavior, 18(2), 411 - 418. doi:10.1007/s10461-013-0518-9
    • Seaman S, Pavlou M, Copas A (2014). Review of methods for handling confounding by cluster and informative cluster size in clustered data.. Stat Med, , - . doi:10.1002/sim.6277
    • Prah P, Copas AJ, Mercer CH, Clifton S, Erens B, Phelps A, Tanton C, Sonnenberg P, Macdowall W, Wellings K, Johnson AM (2014). Consistency in reporting sensitive sexual behaviours in Britain: change in reporting bias in the second and third National Surveys of Sexual Attitudes and Lifestyles (Natsal-2 and Natsal-3). Sexually Transmitted Infections, 90(2), 90 - 93. doi:10.1136/sextrans-2013-051360
    • Sacks RJ, Wilkinson DM, Copas AJ, Robinson AJ (2014). Uptake of the HPV vaccination programme in England: A cross-sectional survey of young women attending sexual health services. Sexually Transmitted Infections, 90(4), 315 - 321. doi:10.1136/sextrans-2013-051179
    • Seaman SR, Pavlou M, Copas AJ (2014). Methods for observed-cluster inference when cluster size is informative: A review and clarifications. Biometrics, 70(2), 449 - 456. doi:10.1111/biom.12151
    • Sabin T, Bray S, Copas A, Parmar MKB, Matcham J (2014). A Quantitative Process for Enhancing End of Phase 2 Decisions. Statistics in Biopharmaceutical Research, 6(1), 67 - 77. doi:10.1080/19466315.2013.852617
    • Gupta RK, Marks M, Edwards SG, Smith K, Fletcher K, Lee SM, Ramsay A, Copas AJ, Miller RF (2014). A Declining CD4 Count and Diagnosis of HIV-Associated Hodgkin Lymphoma: Do Prior Clinical Symptoms and Laboratory Abnormalities Aid Diagnosis?. PLoS One, 9(2), e87442 - . doi:10.1371/journal.pone.0087442
    • Erens B, Phelps A, Clifton S, Mercer CH, Tanton C, Hussey D, Sonnenberg P, Macdowall W, Field N, Datta J, Mitchell K, Copas AJ, Wellings K, Johnson AM (2014). Methodology of the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Sexually Transmitted Infections, 90(2), 84 - 89. doi:10.1136/sextrans-2013-051359
    • Stephenson J, Patel D, Barrett G, Howden B, Copas A, Ojukwu O, Pandya P, Shawe J (2014). How Do Women Prepare for Pregnancy? Preconception Experiences of Women Attending Antenatal Services and Views of Health Professionals.. PLoS One, 9(7), e103085 - . doi:10.1371/journal.pone.0103085

    2013

    • Wayal S, Cassell J, Copas A, Edwards S, Hart G (2013). Repeat cross-sectional survey of sexual behaviour and partnerships of HIV-positive MSM attending a HIV clinic in London, UK: implications for HIV prevention among MSM.
    • Pavlou M, Seaman SR, Copas AJ (2013). An examination of a method for marginal inference when the cluster size is informative. Statistica Sinica, 23(2), 791 - 801. doi:10.5705/ss.2011.252
    • Bailey JV, Pavlou M, Copas A, McCarthy O, Carswell K, Rait G, Hart G, Nazareth I, Free C, French R, Murray E (2013). The sexunzipped trial: optimizing the design of online randomized controlled trials.. J Med Internet Res, 15(12), e278 - . doi:10.2196/jmir.2668
    • Macdowall W, Gibson LJ, Lewis R, Datta J, Mitchell KR, Wellings K, Erens B, Tanton C, Mercer CH, Clifton S, Field N, Sonnenberg P, Copas AJ, Prah P, Johnson AM, Phelps A (2013). Lifetime prevalence, associated factors, and circumstances of non-volitional sex in women and men in Britain: Findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). The Lancet, 382(9907), 1845 - 1855. doi:10.1016/S0140-6736(13)62300-4
    • Mitchell KR, Datta J, Macdowall W, Wellings K, Ploubidis GB, Mercer CH, Jones KG, Field N, Copas AJ, Tanton C, Erens B, Sonnenberg P, Clifton S, Johnson AM, Phelps A (2013). Sexual function in Britain: Findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). The Lancet, 382(9907), 1817 - 1829. doi:10.1016/S0140-6736(13)62366-1
    • Sonnenberg P, Clifton S, Beddows S, Field N, Soldan K, Tanton C, Mercer CH, da Silva FC, Alexander S, Copas AJ, Phelps A, Erens B, Prah P, Macdowall W, Wellings K, Ison CA, Johnson AM (2013). Prevalence, risk factors, and uptake of interventions for sexually transmitted infections in Britain: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal). The Lancet, 382(9907), 1795 - 1806. doi:10.1016/S0140-6736(13)61947-9
    • Prost A, Colbourn T, Seward N, Azad K, Coomarasamy A, Copas A, Houweling TA, Fottrell E, Kuddus A, Lewycka S, MacArthur C, Manandhar D, Morrison J, Mwansambo C, Nair N, Nambiar B, Osrin D, Pagel C, Phiri T, Pulkki-Brännström AM, Rosato M, Skordis-Worrall J, Saville N, More NS, Shrestha B, Tripathy P, Wilson A, Costello A (2013). Women's groups practising participatory learning and action to improve maternal and newborn health in low-resource settings: a systematic review and meta-analysis.. Lancet, 381(9879), 1736 - 1746. doi:10.1016/S0140-6736(13)60685-6
    • Haddow LJ, Floyd S, Copas A, Gilson RJ (2013). A systematic review of the screening accuracy of the HIV Dementia Scale and International HIV Dementia Scale.. PLoS One, 8(4), e61826 - . doi:10.1371/journal.pone.0061826
    • Aghaizu A, Mercey D, Copas A, Johnson AM, Hart G, Nardone A (2013). Who would use PrEP? Factors associated with intention to use among MSM in London: a community survey.. Sex Transm Infect, 89(3), 207 - 211. doi:10.1136/sextrans-2012-050648
    • Erens B, Burkill S, Copas A, Couper M, Conrad F (2013). How well do volunteer web panel surveys measure sensitive behaviours in the general population, and can they be improved? A comparison with the third British National Survey of Sexual Attitudes & Lifestyles (Natsal-3).
    • Iwamoto A, Seward N, Prost A, Ellis M, Copas A, Fottrell E, Azad K, Tripathy P, Costello A (2013). Maternal infection and risk of intrapartum death: a population based observational study in South Asia.. BMC Pregnancy Childbirth, 13(1), 245 - . doi:10.1186/1471-2393-13-245
    • Wellings K, Jones KG, Mercer CH, Tanton C, Clifton S, Datta J, Copas AJ, Erens B, Gibson LJ, Macdowall W, Sonnenberg P, Phelps A, Johnson AM (2013). The prevalence of unplanned pregnancy and associated factors in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). The Lancet, 382(9907), 1807 - 1816. doi:10.1016/S0140-6736(13)62071-1
    • Mercer CH, Tanton C, Prah P, Erens B, Sonnenberg P, Clifton S, Macdowall W, Lewis R, Field N, Datta J, Copas AJ, Phelps A, Wellings K, Johnson AM (2013). Changes in sexual attitudes and lifestyles in Britain through the life course and over time: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal). The Lancet, 382(9907), 1781 - 1794. doi:10.1016/S0140-6736(13)62035-8
    • Field N, Mercer CH, Sonnenberg P, Tanton C, Clifton S, Mitchell KR, Erens B, Macdowall W, Wu F, Datta J, Jones KG, Stevens A, Prah P, Copas AJ, Phelps A, Wellings K, Johnson AM (2013). Associations between health and sexual lifestyles in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). The Lancet, 382(9907), 1830 - 1844. doi:10.1016/S0140-6736(13)62222-9
    • Hall J, Barrett G, Mbwana N, Copas A, Malata A, Stephenson J (2013). Understanding pregnancy planning in a low-income country setting: validation of the London measure of unplanned pregnancy in Malawi.. BMC Pregnancy Childbirth, 13(1), 200 - . doi:10.1186/1471-2393-13-200
    • McCreesh N, Copas A, Seeley J, Johnston LG, Sonnenberg P, Hayes RJ, Frost SD, White RG (2013). Respondent driven sampling: determinants of recruitment and a method to improve point estimation.. PLoS One, 8(10), e78402 - . doi:10.1371/journal.pone.0078402
    • Whitlock GG, Copas A, Gilson R, Herbert S, Ainsworth JG (2013). Avascular necrosis in HIV patients: A case-control study. International Journal of STD and AIDS, 24(10), 799 - 803. doi:10.1177/0956462413482814
    • Mavhu W, Berwick J, Chirawu P, Makamba M, Copas A, Dirawo J, Willis N, Araya R, Abas MA, Corbett EL, Mungofa S, Laver SM, Cowan FM (2013). Enhancing Psychosocial Support for HIV Positive Adolescents in Harare, Zimbabwe.. PLoS One, 8(7), e70254 - . doi:10.1371/journal.pone.0070254
    • Price H, Gilson R, Mercey D, Copas A, Parry J, Nardone A, Johnson A, Hart G (2013). Hepatitis C in men who have sex with men in London - a community survey. HIV MEDICINE, 14(9), 578 - 580. doi:10.1111/hiv.12050
    • Stephenson J, Shawe J, Panicker S, Brima N, Copas A, Sauer U, Wilkinson C, Akintomide H, O'Brien P (2013). Randomized trial of the effect of tailored versus standard use of the combined oral contraceptive pill on continuation rates at 1 year.. Contraception, 88(4), 523 - 531. doi:10.1016/j.contraception.2013.03.014
    • Fuller SS, Mercer CH, Copas AJ, Saunders J, Sutcliffe LJ, Cassell JA, Hart GJ, Johnson AM, Roberts T, Jackson L, Muniina P, Estcourt CS (2013). Two urine-based sexually transmitted infection screening interventions targeting young men in football club settings (SPORTSMART): a pilot randomised controlled trial.

    2012

    • Buzdugan R, Watadzaushe C, Dirawo J, Mundida O, Langhaug L, Willis N, Hatzold K, Ncube G, Mugurungi O, Benedikt C, Copas A, Cowan FM (2012). Positive attitudes to pediatric HIV testing: findings from a nationally representative survey from Zimbabwe.. PLoS One, 7(12), e53213 - . doi:10.1371/journal.pone.0053213
    • Bharadwaj P, Akintomide H, Brima N, Copas A, D'Souza R (2012). Determinants of long-acting reversible contraceptive (LARC) use by adolescent girls and young women.. Eur J Contracept Reprod Health Care, 17(4), 298 - 306. doi:10.3109/13625187.2012.675602
    • Fish R, Robinson A, Copas A, Jungmann E, Lascar RM (2012). Trends in attendances to genitourinary medicine services by older women.. Int J STD AIDS, 23(8), 595 - 596. doi:10.1258/ijsa.2012.011426
    • McCreesh N, Frost SD, Seeley J, Katongole J, Tarsh MN, Ndunguse R, Jichi F, Lunel NL, Maher D, Johnston LG, Sonnenberg P, Copas AJ, Hayes RJ, White RG (2012). Evaluation of respondent-driven sampling.. Epidemiology, 23(1), 138 - 147. doi:10.1097/EDE.0b013e31823ac17c
    • Estcourt C, Sutcliffe L, Cassell J, Mercer CH, Copas A, James L, Low N, Horner P, Clarke M, Symonds M, Roberts T, Tsourapas A, Johnson AM (2012). Can we improve partner notification rates through expedited partner therapy in the UK? Findings from an exploratory trial of Accelerated Partner Therapy (APT).. Sex Transm Infect, 88(1), 21 - 26. doi:10.1136/sti.2010.047258
    • Langhaug L, Buzdugan R, Copas A, Dirawo J, Benedict C, Mundida O, Manyenya S, Woelk G, Cowan F (2012). Change over time (2007-2009) in HIV preventive behaviours, evidence from two serial population-based surveys in rural Zimbabwe.. Trop Med Int Health, 17(7), 827 - 835. doi:10.1111/j.1365-3156.2012.02999.x
    • Seaman SR, White IR, Copas AJ, Li L (2012). Combining multiple imputation and inverse-probability weighting.. Biometrics, 68(1), 129 - 137. doi:10.1111/j.1541-0420.2011.01666.x
    • Prost A, Lakshminarayana R, Nair N, Tripathy P, Copas A, Mahapatra R, Rath S, Gope RK, Rath S, Bajpai A, Patel V, Costello A (2012). Predictors of maternal psychological distress in rural India: a cross-sectional community-based study.. J Affect Disord, 138(3), 277 - 286. doi:10.1016/j.jad.2012.01.029
    • Dave SS, Copas A, Richens J, White RG, Kosambiya JK, Desai VK, Stephenson JM (2012). HIV and STI prevalence and determinants among male migrant workers in India.. PLoS One, 7(8), e43576 - . doi:10.1371/journal.pone.0043576
    • Herbert S, Edwards S, Carrick G, Copas A, Sandford C, Amphlett M, Benn P (2012). Evaluation of PIMA point-of-care CD4 testing in a large UK HIV service.. Sex Transm Infect, 88(6), 413 - 417. doi:10.1136/sextrans-2012-050507

    2011

    • Fisher DJ, Copas AJ, Tierney JF, Parmar MK (2011). A critical review of methods for the assessment of patient-level interactions in individual participant data meta-analysis of randomized trials, and guidance for practitioners.. J Clin Epidemiol, 64(9), 949 - 967. doi:10.1016/j.jclinepi.2010.11.016
    • Adlakha A, Pavlou M, Walker DA, Copas AJ, Dufty N, Batson S, Edwards SG, Singer M, Miller RF (2011). Survival of HIV-infected patients admitted to the intensive care unit in the era of highly active antiretroviral therapy.. Int J STD AIDS, 22(9), 498 - 504. doi:10.1258/ijsa.2011.010496
    • Wayal S, Cowan F, Warner P, Copas A, Mabey D, Shahmanesh M (2011). Contraceptive practices, sexual and reproductive health needs of HIV-positive and negative female sex workers in Goa, India.. Sex Transm Infect, 87(1), 58 - 64. doi:10.1136/sti.2010.043158
    • Bowden J, Tierney JF, Copas AJ, Burdett S (2011). Quantifying, displaying and accounting for heterogeneity in the meta-analysis of RCTs using standard and generalised Q statistics.. BMC Med Res Methodol, 11, 41 - . doi:10.1186/1471-2288-11-41
    • Arenas-Pinto A, Grant A, Bhaskaran K, Copas A, Carr A, Worm SW, Martinez E, Reiss P, Dunn D, Weber R, Hoy J, Weller I, Lactic Acidosis Int Study Grp (2011). Risk factors for fatality in HIV-infected patients with dideoxynucleoside-induced severe hyperlactataemia or lactic acidosis. ANTIVIR THER, 16(2), 219 - 226. doi:10.3851/IMP1739
    • Bowden J, Tierney JF, Simmonds M, Copas AJ, Higgins JPT (2011). Individual patient data meta-analysis of time-to-event outcomes: one-stage versus two-stage approaches for estimating the hazard ratio under a random effects model. Research Synthesis Methods, 2(3), 150 - 162. doi:10.1002/jrsm.45
    • Walker K, Seaman SR, De Angelis D, Presanis AM, Dodds JP, Johnson AM, Mercey D, Gill ON, Copas AJ (2011). A synthesis of convenience survey and other data to estimate undiagnosed HIV infection among men who have sex with men in England and Wales.. Int J Epidemiol, 40(5), 1358 - 1366. doi:10.1093/ije/dyr125
    • Sonnenberg P, Copas A, Glynn JR, Bester A, Nelson G, Shearer S, Murray J (2011). The effect of HIV infection on time off work in a large cohort of gold miners with known dates of seroconversion.. Occup Environ Med, 68(9), 647 - 652. doi:10.1136/oem.2010.058487
    • Parkes A, Strange V, Wight D, Bonell C, Copas A, Henderson M, Buston K, Stephenson J, Johnson A, Allen E, Hart G (2011). Comparison of teenagers' early same-sex and heterosexual behavior: UK data from the SHARE and RIPPLE studies.. J Adolesc Health, 48(1), 27 - 35. doi:10.1016/j.jadohealth.2010.05.010
    • McCreesh N, Johnston LG, Copas A, Sonnenberg P, Seeley J, Hayes RJ, Frost SDW, White RG (2011). Evaluation of the role of location and distance in recruitment in respondent-driven sampling. INT J HEALTH GEOGR, 10, - . doi:10.1186/1476-072X-10-56
    • Armstrong-James D, Copas AJ, Walzer PD, Edwards SG, Miller RF (2011). A prognostic scoring tool for identification of patients at high and low risk of death from HIV-associated Pneumocystis jirovecii pneumonia.. Int J STD AIDS, 22(11), 628 - 634. doi:10.1258/ijsa.2011.011040

    2010

    • Adlakha AG, Pavlou M, Walker D, Copas AJ, Batson S, Edwards SG, Singer M, Miller RF (2010). SURVIVAL OF HIV-INFECTED PATIENTS ADMITTED TO THE INTENSIVE CARE UNIT. doi:10.1136/thx.2010.150938.33
    • Richens J, Copas A, Sadiq ST, Kingori P, McCarthy O, Jones V, Hay P, Miles K, Gilson R, Imrie J, Pakianathan M (2010). A randomised controlled trial of computer-assisted interviewing in sexual health clinics.. Sex Transm Infect, 86(4), 310 - 314. doi:10.1136/sti.2010.043422
    • Turner J, Aarons E, O'Farrell S, Price H, Ferns B, Copas A, Gilson R (2010). Hepatitis C viral load in semen of HIV-positive men during acute and chronic hepatitis C infection.
    • Gilson RJ, Man SL, Copas A, Rider A, Forsyth S, Hill T, Bansi L, Porter K, Gazzard B, Orkin C, Pillay D, Schwenk A, Johnson M, Easterbook P, Walsh J, Fisher M, Leen C, Anderson J, Sabin CA, UK Collaborative HIV Cohort Study Group (2010). Discordant responses on starting highly active antiretroviral therapy: suboptimal CD4 increases despite early viral suppression in the UK Collaborative HIV Cohort (UK CHIC) Study.. HIV Med, 11(2), 152 - 160. doi:10.1111/j.1468-1293.2009.00755.x
    • Armstrong-James D, Copas AJ, Walzer PD, Edwards SG, Miller RF (2010). PREDICTING OUTCOME FROM HIV-ASSOCIATED PNEUMOCYSTIS PNEUMONIA. doi:10.1136/thx.2010.150946.30
    • Copas AJ, Pavlou M, Seaman SR (2010). Joint models for outcome and the (informative) number of measurements.
    • Miller RF, Evans HE, Copas AJ, Huggett JF, Edwards SG, Walzer PD (2010). Seasonal variation in mortality of Pneumocystis jirovecii pneumonia in HIV-infected patients.. Int J STD AIDS, 21(7), 497 - 503. doi:10.1258/ijsa.2010.010148
    • Buzdugan R, Copas A, Moses S, Blanchard J, Isac S, Ramesh BM, Washington R, Halli SS, Cowan FM (2010). Devising a female sex work typology using data from Karnataka, India.. Int J Epidemiol, 39(2), 439 - 448. doi:10.1093/ije/dyp351
    • Sage EK, Noursadeghi M, Evans HE, Parker SJ, Copas AJ, Edwards SG, Miller RF (2010). Prognostic value of C-reactive protein in HIV-infected patients with Pneumocystis jirovecii pneumonia.. Int J STD AIDS, 21(4), 288 - 292. doi:10.1258/ijsa.2010.009551
    • Copas AJ, Seaman SR (2010). Bias from the use of generalized estimating equations to analyze incomplete longitudinal binary data. J APPL STAT, 37(6), 911 - 922. doi:10.1080/02664760902939604
    • Harte D, Dosekun O, Sethi G, Chadborn T, de Ruiter A, Copas A, Edwards SG, Miller RF (2010). Immunosuppression among HIV-1-positive patients attending for care: experience from two large HIV centres in the United Kingdom.. HIV Med, 11(2), 114 - 120. doi:10.1111/j.1468-1293.2009.00753.x
    • Rosenvinge MM, Gedela K, Copas AJ, Wilkinson A, Sheehy CA, Bano G, Hay PE, Pakianathan MR, Sadiq ST (2010). Tenofovir-linked hyperparathyroidism is independently associated with the presence of vitamin D deficiency.. J Acquir Immune Defic Syndr, 54(5), 496 - 499.

    2009

    • Fisher D, Copas AJ, Tierney J, Parmar M (2009). A critical review of methods and guidance on the assessment of interactions in individual patient data (IPD) meta analysis.
    • Ewings F, Copas A, Fidler S, McLean K, Fisher M, Phillips A, Porter K, Hawkins D, Gilson R, Johnson M (2009). HIV-infected individuals co-infected with hepatitis C appear to have faster CD4 decline in the absence of ART but similar response once combination ART is initiated..
    • Shahmanesh M, Wayal S, Cowan F, Mabey D, Copas A, Patel V (2009). Suicidal behavior among female sex workers in Goa, India: the silent epidemic.. Am J Public Health, 99(7), 1239 - 1246. doi:10.2105/AJPH.2008.149930
    • Mercer CH, Copas AJ, Sonnenberg P, Johnson AM, McManus S, Erens B, Cassell JA (2009). Who has sex with whom? Characteristics of heterosexual partnerships reported in a national probability survey and implications for STI risk.. Int J Epidemiol, 38(1), 206 - 214. doi:10.1093/ije/dyn216
    • Woodward CL, Hall AM, Williams IG, Madge S, Copas A, Nair D, Edwards SG, Johnson MA, Connolly JO (2009). Tenofovir-associated renal and bone toxicity.. HIV Med, 10(8), 482 - 487. doi:10.1111/j.1468-1293.2009.00716.x
    • Seaman S, Copas A (2009). Doubly robust generalized estimating equations for longitudinal data.. Stat Med, 28(6), 937 - 955. doi:10.1002/sim.3520
    • Shahmanesh M, Cowan F, Wayal S, Copas A, Patel V, Mabey D (2009). The burden and determinants of HIV and sexually transmitted infections in a population-based sample of female sex workers in Goa, India.. Sex Transm Infect, 85(1), 50 - 59. doi:10.1136/sti.2008.030767
    • Copas AJ, Mercer CH, Farewell VT, Nanchahal K, Johnson AM (2009). Recent heterosexual partnerships and patterns of condom use: a weighted analysis.. Epidemiology, 20(1), 44 - 51. doi:10.1097/EDE.0b013e318187ac81
    • Seaman S, White I, Copas AJ (2009). Combining multiple imputation and inverse probability weighting.
    • Pavlou M, Copas AJ, Seaman S (2009). Efficient weighted generalised estimating equations when the cluster size or covariate structure are informative.
    • Estcourt C, Theobald N, Evans D, Lomax N, Copas A, David L, Edwards A, Fisher M, British Association for Sexual Health and HIV Undergraduate Working Group (2009). How do UK medical graduates rate their knowledge and skills in sexual health and HIV medicine? A national survey.. Int J STD AIDS, 20(5), 324 - 329. doi:10.1258/ijsa.2008.008325
    • Harrison L, Dunn DT, Green H, Copas AJ (2009). Modelling the association between patient characteristics and the change over time in a disease process using observational cohort data.
    • Harrison L, Dunn DT, Green H, Copas AJ (2009). Modelling the association between patient characteristics and the change over time in a disease measure using observational cohort data.. Stat Med, 28(26), 3260 - 3275. doi:10.1002/sim.3725
    • Shahmanesh M, Wayal S, Copas A, Patel V, Mabey D, Cowan F (2009). A study comparing sexually transmitted infections and HIV among ex-red-light district and non-red-light district sex workers after the demolition of Baina red-light district.. J Acquir Immune Defic Syndr, 52(2), 253 - 257. doi:10.1097/QAI.0b013e3181ab6d75

    2008

    • Richens J, Copas A, Sadiq ST, Kingori P, McCarthy O, Jones V, Hay P, Miles K, Gilson R, Imrie J, Pakianathan M (2008). A three-arm randomised controlled trial comparing computer-assisted self-interview with computer-assisted physician interview and pen and paper face-to-face sexual history taking in a clinic setting..
    • Turner J, Gikanga T, Jones V, Copas A, Cooper J, Stevens J, Aarons E, Gilson R (2008). Is there an unrecognised epidemic of hepatitis C infection in men who have sex with men?.
    • Stephenson J, Strange V, Allen E, Copas A, Johnson A, Bonell C, Babiker A, Oakley A, RIPPLE Study Team (2008). The long-term effects of a peer-led sex education programme (RIPPLE): a cluster randomised trial in schools in England.. PLoS Med, 5(11), e224 - . doi:10.1371/journal.pmed.0050224
    • Harte D, Hamill M, Edwards SG, Copas AJ, Minton J, Jones VL, Allason-Jones E, Williams IG, Miller RF (2008). Evaluation of a home-delivery service for HIV-infected patients attending an inner London HIV treatment centre.. Int J STD AIDS, 19(8), 533 - 535. doi:10.1258/ijsa.2007.007311
    • Lascar RM, Devakumar H, Jungmann E, Copas A, Arthur G, Mercey D (2008). Is vaginal microscopy an essential tool for the management of women presenting with vaginal discharge?. Int J STD AIDS, 19(12), 859 - 860. doi:10.1258/ijsa.2008.008212
    • Copas A, Seaman S, Raab G, Jewell CP, Presanis A, Sweeting M, Bird SM, Calleja N, Farrington CP, Greenland S, Kalogeropoulos K, Papaspiliopoulos O, Katki HA, Raftery AE, Alkema L (2008). Discussion on the paper by Goubar, Ades, De Angelis, McGarrigle, Mercer, Tookey, Fenton and Gill. J ROY STAT SOC A STA, 171, 568 - 580.
    • Brown L, Copas A, Stephenson J, Gilleran G, Ross JD (2008). Preferred options for receiving sexual health screening results: a population and patient survey.. Int J STD AIDS, 19(3), 184 - 187. doi:10.1258/ijsa.2007.007172
    • Grover D, Copas A, Green H, Edwards SG, Dunn DT, Sabin C, Phillips A, Allen E, Pillay D, UK Collaborative Group on HIV Drug Resistance and UK Collaborative HIV Cohort Study (UK CHIC) (2008). What is the risk of mortality following diagnosis of multidrug-resistant HIV-1?. J Antimicrob Chemother, 61(3), 705 - 713. doi:10.1093/jac/dkm522
    • Walzer PD, Evans HE, Copas AJ, Edwards SG, Grant AD, Miller RF (2008). Early predictors of mortality from Pneumocystis jirovecii pneumonia in HIV-infected patients: 1985-2006.. Clin Infect Dis, 46(4), 625 - 633. doi:10.1086/526778
    • Roedling S, Reeves I, Copas AJ, Beattie A, Edwards SG, Fisher M, Benn P (2008). Changes in the provision of post-exposure prophylaxis for HIV after sexual exposure following introduction of guidelines and publicity campaigns.. Int J STD AIDS, 19(4), 241 - 242. doi:10.1258/ijsa.2007.007216

    2007

    • Benn PD, Rooney G, Carder C, Brown M, Stevenson SR, Copas A, Robinson AJ, Ridgway GL (2007). Chlamydia trachomatis and Neisseria gonorrhoeae infection and the sexual behaviour of men who have sex with men.. Sex Transm Infect, 83(2), 106 - 112. doi:10.1136/sti.2006.021329
    • Allen E, Bonell C, Strange V, Copas A, Stephenson J, Johnson AM, Oakley A (2007). Does the UK government's teenage pregnancy strategy deal with the correct risk factors? Findings from a secondary analysis of data from a randomised trial of sex education and their implications for policy.. J Epidemiol Community Health, 61(1), 20 - 27. doi:10.1136/jech.2005.040865
    • Hamill M, Benn P, Carder C, Copas A, Ward H, Ison C, French P (2007). The clinical manifestations of anorectal infection with lymphogranuloma venereum (LGV) versus non-LGV strains of Chlamydia trachomatis: a case-control study in homosexual men.. Int J STD AIDS, 18(7), 472 - 475. doi:10.1258/095646207781147319
    • Miller RF, Evans HE, Copas AJ, Cassell JA (2007). Climate and genotypes of Pneumocystis jirovecii.. Clin Microbiol Infect, 13(4), 445 - 448. doi:10.1111/j.1469-0691.2006.01641.x
    • Evans HER, Copas AJ, Petersen I, Mercer CH, Rait G, Singh S, Williams T, Cassell JA (2007). A validation study to confirm the reliability of primary care consultation data provided by the UK General Practice Research Database..
    • Seaman SR, Copas AJ (2007). Doubly robust generalised estimating equations approach for repeated binary data.
    • Mercer CH, Fenton KA, Wellings K, Copas AJ, Erens B, Johnson AM (2007). Sex partner acquisition while overseas: results from a British national probability survey.. Sex Transm Infect, 83(7), 517 - 522. doi:10.1136/sti.2007.026377
    • Copas AJ, Seaman SR (2007). Bias from the use of generalised estimating equations to analyse incomplete longitudinal binary data.
    • Copas AJ, Seaman SR (2007). Bias from the use of generalised estimating equations to analyse incomplete longitudinal binary data.
    • Arenas-Pinto A, Copas A, Weller I, Grant A, Dunn D, Bhaskaran K, Carr A, Reiss P, Edwards S, Worm SW, Overton T, Martinez E, Hoy J, Cahn P, Weber R (2007). Risk factors for lactic acidosis and severe hyperlactataemia in HIV-1-infected adults exposed to antiretroviral therapy. AIDS, 21(18), 2455 - 2464. doi:10.1097/QAD.0b013e3282f08cdc
    • Osmond MK, Copas AJ, Newey C, Edwards SG, Jungmann E, Mercey D (2007). The use of chaperones for intimate examinations: the patient perspective based on an anonymous questionnaire.. Int J STD AIDS, 18(10), 667 - 671. doi:10.1258/095646207782193759
    • Sarner L, Fakoya AO, Tawana C, Allen E, Copas AJ, Chiodini PL, Fenton KA (2007). The utility of screening for parasitic infections in HIV-1-infected Africans with eosinophilia in London.. Int J STD AIDS, 18(9), 626 - 629. doi:10.1258/095646207781568420
    • Ross JD, Copas A, Stephenson J, Fellows L, Gilleran G (2007). Optimizing information technology to improve sexual health-care delivery: public and patient preferences.. Int J STD AIDS, 18(7), 440 - 445. doi:10.1258/095646207781147210
    • Mercer CH, Bailey JV, Johnson AM, Erens B, Wellings K, Fenton KA, Copas AJ (2007). Women who report having sex with women: British national probability data on prevalence, sexual behaviors, and health outcomes.. Am J Public Health, 97(6), 1126 - 1133. doi:10.2105/AJPH.2006.086439
    • Edwards SG, Grover D, Scott C, Tedder RS, Pillay D, Copas A, Miller RF (2007). Cytomegalovirus viral load testing of blood using quantitative polymerase chain reaction in acutely unwell HIV-1-positive patients lacks diagnostic utility.. Int J STD AIDS, 18(5), 321 - 323. doi:10.1258/095646207780749600
    • Dickson SJ, Batson S, Copas AJ, Edwards SG, Singer M, Miller RF (2007). Survival of HIV-infected patients in the intensive care unit in the era of highly active antiretroviral therapy.. Thorax, 62(11), 964 - 968. doi:10.1136/thx.2006.072256

    2006

    • Ross JD, Copas A, Stephenson J, Fellows L, Gilleran G (2006). Public involvement in modernising genitourinary medicine clinics: using general public and patient opinion to influence models of service delivery.. Sex Transm Infect, 82(6), 484 - 488. doi:10.1136/sti.2006.020750
    • Cassell JA, Mercer CH, Fenton KA, Copas AJ, Erens B, Wellings K, Johnson AM (2006). A comparison of the population diagnosed with chlamydia in primary care with that diagnosed in sexual health clinics: implications for a national screening programme.. Public Health, 120(10), 984 - 988. doi:10.1016/j.puhe.2006.05.025
    • Sadler K, Evans HER, Sutcliffe L, Mercer CH, Copas AJ, Cassell JA, Low N (2006). Exploring the use of proxies for the sexual health of a population.
    • Gilbart VL, Mercer CH, Dougan S, Copas AJ, Fenton KA, Johnson AM, Evans BG (2006). Factors associated with heterosexual transmission of HIV to individuals without a major risk within England, Wales, and Northern Ireland: a comparison with national probability surveys.. Sex Transm Infect, 82(1), 15 - 20. doi:10.1136/sti.2004.014191
    • Hamill M, Copas A, Murphy SM (2006). Incentives for voluntary HIV testing in NHS staff.. Occup Med (Lond), 56(6), 426 - 429. doi:10.1093/occmed/kql054
    • Bailey JV, Mercer CH, Johnson AM, Erens B, Wellings K, Fenton KA, Copas AJ (2006). Women who report sex with women in Britain: national probability data on prevalence, sexual behaviors and health outcomes..
    • McGarrigle CA, Cliffe S, Copas AJ, Mercer CH, DeAngelis D, Fenton KA, Evans BG, Johnson AM, Gill ON (2006). Estimating adult HIV prevalence in the UK in 2003: the direct method of estimation.. Sex Transm Infect, 82 Suppl 3, iii78 - iii86. doi:10.1136/sti.2006.020339
    • Saxena S, Copas AJ, Mercer C, Johnson AM, Fenton K, Erens B, Nanchahal K, Macdowall W, Wellings K (2006). Ethnic variations in sexual activity and contraceptive use: national cross-sectional survey.. Contraception, 74(3), 224 - 233. doi:10.1016/j.contraception.2006.03.025
    • Turner JM, Rider AT, Imrie J, Copas AJ, Edwards SG, Dodds JP, Stephenson JM (2006). Behavioural predictors of subsequent hepatitis C diagnosis in a UK clinic sample of HIV positive men who have sex with men.. Sex Transm Infect, 82(4), 298 - 300. doi:10.1136/sti.2005.018366
    • Miller RF, Allen E, Copas A, Singer M, Edwards SG (2006). Improved survival for HIV infected patients with severe Pneumocystis jirovecii pneumonia is independent of highly active antiretroviral therapy.. Thorax, 61(8), 716 - 721. doi:10.1136/thx.2005.055905
    • Mercer CH, Wellings K, Macdowall W, Copas AJ, McManus S, Erens B, Fenton KA, Johnson AM (2006). First sexual partnerships--age differences and their significance: empirical evidence from the 2000 British National Survey of Sexual Attitudes and Lifestyles ('Natsal 2000').. J Adolesc Health, 39(1), 87 - 95. doi:10.1016/j.jadohealth.2005.10.007
    • Macdowall W, Wellings K, Mercer CH, Nanchahal K, Copas AJ, McManus S, Fenton KA, Erens B, Johnson AM (2006). Learning about sex: results from Natsal 2000.. Health Educ Behav, 33(6), 802 - 811. doi:10.1177/1090198106289003
    • Dodds JP, Mercer CH, Mercey DE, Copas AJ, Johnson AM (2006). Men who have sex with men: a comparison of a probability sample survey and a community based study.. Sex Transm Infect, 82(1), 86 - 87. doi:10.1136/sti.2005.015248
    • Newton PJ, Weller IV, Williams IG, Miller RF, Copas A, Tedder RS, Katz DR, Chain BM (2006). Monocyte derived dendritic cells from HIV-1 infected individuals partially reconstitute CD4 T-cell responses.. AIDS, 20(2), 171 - 180. doi:10.1097/01.aids.0000202649.95655.8c
    • Imrie J, Lambert N, Mercer CH, Copas AJ, Phillips A, Dean G, Watson R, Fisher M (2006). Refocusing health promotion for syphilis prevention: results of a case-control study of men who have sex with men on England's south coast.. Sex Transm Infect, 82(1), 80 - 83. doi:10.1136/sti.2005.015156
    • Bonell C, Allen E, Strange V, Oakley A, Copas A, Johnson A, Stephenson J (2006). Influence of family type and parenting behaviours on teenage sexual behaviour and conceptions.. J Epidemiol Community Health, 60(6), 502 - 506. doi:10.1136/jech.2005.042838
    • Mercer CH, Fenton KA, Johnson AM, Copas AJ, Macdowall W, Erens B, Wellings K (2006). Who reports sexual function problems? Evidence from the 2000 National Survey of Sexual Attitudes and Lifestyles (‘Natsal 2000’)..
    • Cassell JA, Mercer CH, Imrie J, Copas AJ, Johnson AM (2006). Who uses condoms with whom? Evidence from national probability sample surveys.. Sex Transm Infect, 82(6), 467 - 473. doi:10.1136/sti.2005.019117

    2005

    • Fenton KA, Mercer CH, McManus S, Erens B, Wellings K, Macdowall W, Byron CL, Copas AJ, Nanchahal K, Field J, Johnson AM (2005). Ethnic variations in sexual behaviour in Great Britain and risk of sexually transmitted infections: a probability survey.. Lancet, 365(9466), 1246 - 1255. doi:10.1016/S0140-6736(05)74813-3
    • Miller RF, Lindley AR, Copas A, Ambrose HE, Davies RJ, Wakefield AE (2005). Genotypic variation in Pneumocystis jirovecii isolates in Britain.. Thorax, 60(8), 679 - 682. doi:10.1136/thx.2004.039818
    • Miller RF, Lindley AR, Copas A, Ambrose HE, Davies RJO, Wakefield AE (2005). Genotypic variation in Pneumocystis jirovecii isolates in Britain.
    • Sadiq ST, McSorley J, Copas AJ, Bennett J, Edwards SJ, Kaye S, Kirk S, French P, Weller IV (2005). The effects of early syphilis on CD4 counts and HIV-1 RNA viral loads in blood and semen.. Sex Transm Infect, 81(5), 380 - 385. doi:10.1136/sti.2004.012914
    • Mercer CH, Fenton KA, Johnson AM, Copas AJ, Macdowall W, Erens B, Wellings K (2005). Who reports sexual function problems? Empirical evidence from Britain's 2000 National Survey of Sexual Attitudes and Lifestyles.. Sex Transm Infect, 81(5), 394 - 399. doi:10.1136/sti.2005.015149
    • Copas AJ, Mercer CH, Farewell VT, Nanchahal K, Johnson AM (2005). Weighting recent episodes to reflect different populations of interest: with application to heterosexual partnerships in the last year..
    • Mercer CH, Johnson AM, Fenton KA, Copas AJ, Erens B, Wellings K (2005). Prevalence, sexual behaviours and health outcomes among women who report sex with women (WSW): Results of a national probability survey..
    • Ward H, Mercer CH, Wellings K, Fenton K, Erens B, Copas A, Johnson AM (2005). Who pays for sex? An analysis of the increasing prevalence of female commercial sex contacts among men in Britain.. Sex Transm Infect, 81(6), 467 - 471. doi:10.1136/sti.2005.014985
    • Bonell C, Allen E, Strange V, Copas A, Oakley A, Stephenson J, Johnson A (2005). The effect of dislike of school on risk of teenage pregnancy: testing of hypotheses using longitudinal data from a randomised trial of sex education.. J Epidemiol Community Health, 59(3), 223 - 230. doi:10.1136/jech.2004.023374
    • Fenton KA, Mercer CH, Johnson AM, Byron CL, McManus S, Erens B, Copas AJ, Nanchahal K, Macdowall W, Wellings K (2005). Reported sexually transmitted disease clinic attendance and sexually transmitted infections in britain: prevalence, risk factors, and proportionate population burden.. J Infect Dis, 191 Suppl 1, S127 - S138. doi:10.1086/425286
    • McGarrigle CA, Mercer CH, Fenton KA, Copas AJ, Wellings K, Erens B, Johnson AM (2005). Investigating the relationship between HIV testing and risk behaviour in Britain: National Survey of Sexual Attitudes and Lifestyles 2000.. AIDS, 19(1), 77 - 84.
    • Lascar RM, Lopes AR, Gilson RJ, Dunn C, Johnstone R, Copas A, Reignat S, Webster G, Bertoletti A, Maini MK (2005). Effect of HIV infection and antiretroviral therapy on hepatitis B virus (HBV)-specific T cell responses in patients who have resolved HBV infection.. J Infect Dis, 191(7), 1169 - 1179. doi:10.1086/428502
    • Burns F, Fenton KA, Morison L, Mercer C, Erens B, Field J, Copas AJ, Wellings K, Johnson AM (2005). Factors associated with HIV testing among black Africans in Britain.. Sex Transm Infect, 81(6), 494 - 500. doi:10.1136/sti.2004.013755
    • Chilton D, Dervisevic S, Pillay D, Rider A, Copas A, Miller RF, Edwards SG (2005). Determinants of HIV drug resistance mutations in plasma virus after treatment interruption.. AIDS, 19(18), 2174 - 2175.
    • McCadden A, Fenton KA, McManus S, Mercer CH, Erens B, Carder C, Ridgway G, Macdowall W, Nanchahal K, Byron CL, Copas A, Wellings K, Johnson AM (2005). Chlamydia trachomatis testing in the second British national survey of sexual attitudes and lifestyles: respondent uptake and treatment outcomes.. Sex Transm Dis, 32(6), 387 - 394.
    • Sadiq ST, Taylor S, Copas AJ, Bennett J, Kaye S, Drake SM, Kirk S, Pillay D, Weller IV (2005). The effects of urethritis on seminal plasma HIV-1 RNA loads in homosexual men not receiving antiretroviral therapy.. Sex Transm Infect, 81(2), 120 - 123. doi:10.1136/sti.2004.010249
    • Nanchahal K, Wellings K, Barrett G, Copas AJ, Mercer CH, Macmanus S, Macdowall W, Fenton KA, Erens B, Johnson AM (2005). Changes in the circumstances of young mothers in Britain: 1990 to 2000.. J Epidemiol Community Health, 59(10), 828 - 833. doi:10.1136/jech.2004.026021
    • Creighton S, Miller R, Edwards S, Copas A, French P (2005). Is ritonavir boosting associated with gout?. Int J STD AIDS, 16(5), 362 - 364. doi:10.1258/0956462053888808
    • Mercer CH, Fenton KA, Johnson AM, Copas AJ, Erens B, Wellings K (2005). Overseas travel, high-risk sexual behaviour and STI transmission risk among British adults: Results of a national probability survey of sexual attitudes and lifestyles..
    • Grover D, Allen L, Edwards SG, Green H, Copas A, Forsyth S, Pillay D, UK Collaborative Grp HIV Drug , UK Collaborative HIV Cohort Study (2005). Predictors of death, and response to therapy in patients with multi (three)-class drug resistant (MDR) HIV in the UK..

    2004

    • Mercer CH, Copas AJ, Fenton KA, Wellings K, Erens B, Johnson AM (2004). Who has sex with whom? Analyses of heterosexual partnerships in the last year reported in the National Survey of Sexual Attitudes and Lifestyles 2000 (‘Natsal 2000’)..
    • Stephenson JM, Strange V, Forrest S, Oakley A, Copas A, Allen E, Babiker A, Black S, Ali M, Monteiro H, Johnson AM, RIPPLE study team (2004). Pupil-led sex education in England (RIPPLE study): cluster-randomised intervention trial. LANCET, 364(9431), 338 - 346.
    • Haddow LJ, Bunn A, Copas AJ, Gilson R, Prince M, Ridgway GL, Sadiq ST (2004). Polymorph count for predicting non-gonococcal urethral infection: a model using Chlamydia trachomatis diagnosed by ligase chain reaction.. Sex Transm Infect, 80(3), 198 - 200.
    • Mercer CH, Copas AJ, Macdowall W, Erens B, Fenton KA, Johnson AM, Wellings K (2004). First heterosexual partnerships: Age differences and their significance. Empirical evidence from the National Survey of Sexual Attitudes and Lifestyles 2000 (‘Natsal 2000’)..
    • Bourboulia D, Aldam D, Lagos D, Allen E, Williams I, Cornforth D, Copas A, Boshoff C (2004). Short- and long-term effects of highly active antiretroviral therapy on Kaposi sarcoma-associated herpesvirus immune responses and viraemia.. AIDS, 18(3), 485 - 493.
    • Mercer CH, Fenton KA, Copas AJ, Wellings K, Erens B, McManus S, Nanchahal K, Macdowall W, Johnson AM (2004). Increasing prevalence of male homosexual partnerships and practices in Britain 1990-2000: evidence from national probability surveys.. AIDS, 18(10), 1453 - 1458.
    • Copas AJ, Farewell VT, Mercer CH, Yao GQ (2004). The sensitivity of estimates of the change in population behaviour to realistic changes in bias in repeated surveys. J ROY STAT SOC A STA, 167, 579 - 595.
    • Rogstad KE, Copas AJ (2004). The impact of pump-priming funding on genitourinary medicine and modernization of services.. Int J STD AIDS, 15(10), 653 - 657.
    • Mercer CH, Copas AJ, Fenton KA, Wellings K, Erens B, Johnson AM (2004). Who has sex with whom? Analysis of heterosexual partnerships in the last year reported in the National Survey of Sexual Attitudes and Lifestyles 2000..
    • Lambert NL, Imrie J, Mercer CH, Fisher M, Dean G, Watson R, Phillips A, Copas AJ (2004). Syphilis and drug use among men who have sex with men..
    • Mercer CH, Copas AJ, Macdowell W, Erens B, Fenton KA, Johnson AM, Wellings K (2004). First heterosexual partnerships: Age difference and their significance. Empirical evidence from the National Survey of Sexual Attitudes and Lifestyles 2000 (`Natsal 2000`).
    • Burns F, Fenton KA, Morison LA, Mercer CH, Erens B, Field J, Copas A, Wellings K, Johnson AM (2004). Factors associated with HIV testing amongst heterosexually experienced black Africans in the National Survey of Sexual Attitudes and Lifestyles 2000 survey.
    • Copas AJ, Charman S, Farewell VT, Omar RZ (2004). Efficient marginal regression where cluster structure is informative..
    • Imrie J, Lambert NL, Phillips A, Mercer CH, Copas AJ, Watson R, Perry N, Dean G, Fisher M (2004). Demographic, sexual partnerships and sexual behaviours associated with recent syphilis diagnosis among men who have sex with men (MSM) on England’s south coast..
    • Imrie J, Stephenson JM, Mercer CH, Copas AJOBOTBIGPSG (2004). ‘When the intervention fails to deliver’: Lessons from a negative trial of behavioural intervention with gay men attending a genitourinary medicine clinic..
    • Walker K, Omar RZ, Copas AJ (2004). The effect of missing observations on parameter estimates and significance from clustered data in health studies..

    2003

    • Stephenson JM, Imrie J, Davis MM, Mercer C, Black S, Copas AJ, Hart GJ, Davidson OR, Williams IG (2003). Is use of antiretroviral therapy among homosexual men associated with increased risk of transmission of HIV infection?. Sex Transm Infect, 79(1), 7 - 10.
    • Stephenson JM, Oakley A, Johnson AM, Forrest S, Strange V, Charleston S, Black S, Copas A, Petruckevitch A, Babiker A (2003). A school-based randomized controlled trial of peer-led sex education in England.. Control Clin Trials, 24(5), 643 - 657.
    • Stephenson J, Hopwood J, Babiker A, Copas A, Vickers M (2003). Recent pilot studies of chlamydia screening.. Sex Transm Infect, 79(4), 352 - .
    • Bonell CP, Strange VJ, Stephenson JM, Oakley AR, Copas AJ, Forrest SP, Johnson AM, Black S (2003). Effect of social exclusion on the risk of teenage pregnancy: development of hypotheses using baseline data from a randomised trial of sex education.. J Epidemiol Community Health, 57(11), 871 - 876.
    • Erens B, McManus S, Prescott P, Field J, Johnson A, Wellings K, Fenton K, Mercer C, Macdowall W, Copas A, Nanchahal K (2003). National Survey of Sexual Attitudes and Lifestyles II: reference tables and summary report..
    • Benn P, Ruff C, Cartledge J, Sauret V, Copas A, Linney A, Williams IG, Smith C, Edwards SG (2003). Overcoming subjectivity in assessing facial lipoatrophy: is there a role for three-dimensional laser scans?. HIV Med, 4(4), 325 - 331.
    • McManus S, Prescott A, Erens B, Field J, On BOTNIITW, MacDowall W, Nanchahal K, Johnson AM, Fenton K, Copas A, Mercer C (2003). Risk taking behaviour: National Survey of Sexual Attitudes and Lifestyles.
    • Smith R, Copas AJ, Prince M, George B, Walker AS, Sadiq ST (2003). Poor sensitivity and consistency of microscopy in the diagnosis of low grade non-gonococcal urethritis.. Sex Transm Infect, 79(6), 487 - 490.
    • Taylor S, Sadiq ST, Weller I, Kaye S, Workman J, Cane PA, Bennett J, Copas AJ, Drake SM, Pillay D (2003). Drug-resistant HIV-1 in the semen of men receiving antiretroviral therapy with acute sexually transmitted infections.. Antivir Ther, 8(5), 479 - 483.

    2002

    • Benn P, Rooney G, Brown M, Carder C, Copas A, Robinson A, Ridgway G (2002). Screening in homosexual men: are we doing enough?.
    • Copas AJ, Wellings K, Erens B, Mercer CH, McManus S, Fenton KA, Korovessis C, Macdowall W, Nanchahal K, Johnson AM (2002). The accuracy of reported sensitive sexual behaviour in Britain: exploring the extent of change 1990-2000.. Sex Transm Infect, 78(1), 26 - 30.
    • Sadiq ST, Taylor S, Kaye S, Bennett J, Johnstone R, Byrne P, Copas AJ, Drake SM, Pillay D, Weller I (2002). The effects of antiretroviral therapy on HIV-1 RNA loads in seminal plasma in HIV-positive patients with and without urethritis.. AIDS, 16(2), 219 - 225.
    • Cowan FM, Copas A, Johnson AM, Ashley R, Corey L, Mindel A (2002). Herpes simplex virus type 1 infection: a sexually transmitted infection of adolescence?. Sex Transm Infect, 78(5), 346 - 348.
    • Fenton KA, Chinouya M, Davidson O, Copas A, MAYISHA study team (2002). HIV testing and high risk sexual behaviour among London's migrant African communities: a participatory research study.. Sex Transm Infect, 78(4), 241 - 245.
    • McManus S, Field J, Prescott A, Erens B, on behalf of the Natsal II team Wellings K, Macdowall W, Nanchahal K, Johnson AM, Fenton KA, Copas AJ, Mercer CH (2002). Risk-taking: National Survey of Sexual Attitudes and Lifestyles..
    • McManus S, Prescott A, Erens B, Field JOBOTNIITWK, Macdowall W, Nanchahal K, Johnson AM, Fenton KA, Copas AJ, Mercer CH (2002). Sexual attitudes: National Survey of Sexual Attitudes and Lifestyles..
    • McManus S, Field J, Prescott A, Erens B, On Behalf of the NATSAL II Team W, K M, W N, K J, A M F, K A C, A J M, C H (2002). Sexual behaviour: National survey of sexual attitudes and lifestyles.
    • Korovessis C, McManus S, Fenton K, Erens B, Mercer C, Johnson AM, Copas A, MacDowall W, Wellings K, Nanchahal K, Field J (2002). Exploring the impact of nonresponse to urine sampling on estimates of Chlamydia Trachomatis prevalence. [Abstract].
    • Erens B, Field J, McManus S, Prescott A, On Behalf of the NATSAL II Team W, K M, W N, K J, A M F, K A C, A J M, C H (2002). Abortion, miscarriage and stillbirth: National survey of sexual attitudes and lifestyles.
    • Erens B, Field J, McManus S, Prescott A, On Behalf of the NATSAL II Team W, K M, W N, K J, A M F, K A C, A J M, C H (2002). Contraception, sources of advice and supply: National survey of sexual attitudes and lifestyles.
    • Korovessis C, McManus S, Fenton KA, Erens B, Mercer CH, Johnson AM, Copas AJ, Macdowall W, Wellings K, Nanchahal K, Field J (2002). Exploring the impact of non-response to urine sampling on estimates of Chlamydia Trachomatis prevalence..
    • Fenton KA, Korovessis C, Johnson AM, McCadden A, McManus S, Wellings K, Mercer CH, Carder C, Copas AJ, Nanchahal K, MacDowall W, Ridgway GL (2002). The prevalence of genital Chlamydia trachomatis infection in Britain: results from a national probability sample survey.
    • Erens B, Field J, McManus S, Prescott AOBOTNIITW, K M, W N, K J, A M F, K A C, A J M, C H (2002). Topic report four: Abortion, miscarriage and stillbirth: National Survey of Sexual Attitudes and Lifestyles..
    • Copas AJ, Cowan FM, Cunningham AL, Mindel A (2002). An evidence based approach to testing for antibody to herpes simplex virus type 2.. Sex Transm Infect, 78(6), 430 - 434.

    2001

    • Benn P, Rooney G, Brown M, Carder C, Copas AJ, Robinson A, Ridgway G (2001). The performance of the ligase chain reaction (LCR) in determining the prevalence of pharyngeal urethral and rectal Chlamdyia trachomatis and Neisseria gonorrhoeae in homosexual men.
    • Fenton KA, Korovessis C, Johnson AM, McCadden A, McManus S, Wellings K, Mercer CH, Carder C, Copas AJ, Nanchahal K, Macdowall W, Ridgway G, Field J, Erens B (2001). Sexual behaviour in Britain: reported sexually transmitted infections and prevalent genital Chlamydia trachomatis infection.. Lancet, 358(9296), 1851 - 1854. doi:10.1016/S0140-6736(01)06886-6
    • Johnson AM, Mercer CH, Erens B, Copas AJ, McManus S, Wellings K, Fenton KA, Korovessis C, Macdowall W, Nanchahal K, Purdon S, Field J (2001). Sexual behaviour in Britain: partnerships, practices, and HIV risk behaviours.. Lancet, 358(9296), 1835 - 1842. doi:10.1016/S0140-6736(01)06883-0
    • Fenton KA, Chinouya M, Davidson O, Copas A, MAYISHA research team (2001). HIV transmission risk among sub-Saharan Africans in London travelling to their countries of origin.. AIDS, 15(11), 1442 - 1445.
    • Copas AJ, Farewell VT (2001). Incorporating retrospective data into an analysis of time to illness.. Biostatistics, 2(1), 1 - 12. doi:10.1093/biostatistics/2.1.1
    • Wellings K, Nanchahal K, Macdowall W, McManus S, Erens B, Mercer CH, Johnson AM, Copas AJ, Korovessis C, Fenton KA, Field J (2001). Sexual behaviour in Britain: early heterosexual experience.. Lancet, 358(9296), 1843 - 1850. doi:10.1016/S0140-6736(01)06885-4
    • Burns FM, Fakoya AO, Copas AJ, French PD (2001). Africans in London continue to present with advanced HIV disease in the era of highly active antiretroviral therapy.. AIDS, 15(18), 2453 - 2455.
    • Fenton KA, Copas A, Mitchell K, Elam G, Carder C, Ridgway G, Wellings K, Erens B, Field J, Johnson AM (2001). The acceptability of urinary LCR testing for Chlamydia trachomatis among participants in a probability sample survey of sexual attitudes and lifestyles.. Sex Transm Infect, 77(3), 194 - 198.
    • Copas AJ, Cowan F, Mindel A (2001). Risk scores to improve serological screening for herpes.
    • Johnson AM, Copas AJ, Erens B, Mandalia S, Fenton K, Korovessis C, Wellings K, Field J (2001). Effect of computer-assisted self-interviews on reporting of sexual HIV risk behaviours in a general population sample: a methodological experiment.. AIDS, 15(1), 111 - 115.
    • Imrie J, Stephenson JM, Cowan FM, Wanigaratne S, Billington AJ, Copas AJ, French L, French PD, Johnson AM, Behavioural Intervention in Gay Men Project Study Group (2001). A cognitive behavioural intervention to reduce sexually transmitted infections among gay men: randomised trial.. BMJ, 322(7300), 1451 - 1456.

    2000

    • Copas A, Cowan FM (2000). Using predictive probability to devise and algorithm for HSV antibody testing.
    • Stephenson J, Carder C, Copas A, Robinson A, Ridgway G, Haines A (2000). Home screening for chlamydial genital infection: is it acceptable to young men and women?. Sex Transm Infect, 76(1), 25 - 27.
    • Richens J, Imrie J, Copas A (2000). Condoms and seat belts: the parallels and the lessons.. Lancet, 355(9201), 400 - 403. doi:10.1016/S0140-6736(99)09109-6

    1999

    • Ades AE, Gupta R, Gibb DM, Duong T, Nicoll A, Goldberg D, Stephenson J, Copas A (1999). Selective versus universal antenatal HIV testing: epidemiological and implementational factors in policy choice.. AIDS, 13(2), 271 - 278.
    • Imrie J, Billington A, Chopin M, Copas A, Paragreen S, McOwan A (1999). Young gay and bisexual men and HIV testing in the time of combination therapy : Any new barriers to testing?.
    • Imrie J, Stephenson JM, Cowan FM, Wanigaratne S, Billington A, Copas A, French L, French PD, Johnson AM (1999). A randomised trial of a small-group behavioural intervention with gay men attending an STD clinic : Preliminary Results.

    1998

    • Irving G, Miller D, Robinson A, Reynolds S, Copas AJ (1998). Psychological factors associated with recurrent vaginal candidiasis: a preliminary study.. Sex Transm Infect, 74(5), 334 - 338.
    • Fenton KA, French R, Giesecke J, Johnson AM, Trotter S, Petruckevitch A, Copas A, Keenlyside R, Howson J, Adler MW (1998). An evaluation of partner notification for HIV infection in genitourinary medicine clinics in England.. AIDS, 12(1), 95 - 102.
    • Sadiq ST, Copas AJ, Johnson AM (1998). Factors associated with gonorrhoea in men aware of being positive for HIV infection: case-control study.. BMJ, 317(7165), 1052 - 1053.
    • Copas AJ, Farewell VT (1998). Dealing with non-ignorable non-response by using an 'enthusiasm-to-respond' variable. J ROY STAT SOC A STA, 161, 385 - 396.
    • Copas AJ (1998). Incorporating retrospective data into a pseudolikelihood analysis of time to illness.

    1997

    • Copas AJ, Johnson AM, Wadsworth J (1997). Assessing participation bias in a sexual behaviour survey: implications for measuring HIV risk.. AIDS, 11(6), 783 - 790.
    • Rooney G, Direkze N, Copas A, Gilson RJC (1997). Can we improve compliance with hepatitis B vaccination in genitourinary medicine clinics?.
    • Grun L, Tassano-Smith J, Carder C, Johnson AM, Robinson A, Murray E, Stephenson J, Haines A, Copas A, Ridgway G (1997). Comparison of two methods of screening for genital chlamydial infection in women attending in general practice: cross sectional survey.. BMJ, 315(7102), 226 - 230.
    • Fenton KA, Copas A, Johnson AM, French R, Petruckevitch A, Adler MW (1997). HIV partner notification policy and practice within GUM clinics in England: where are we now?. Genitourin Med, 73(1), 49 - 53.

    1996

    • Mercey D, Helps BA, Copas A, Petruckevitch A, Johnson AM, Spencer J (1996). Voluntary universal antenatal HIV testing.. Br J Obstet Gynaecol, 103(11), 1129 - 1133.
    • Williams DI, Stephenson JM, Hart GJ, Copas A, Johnson AM, Williams IG (1996). A case control study of HIV seroconversion in gay men, 1988-1993: what are the current risk factors?. Genitourin Med, 72(3), 193 - 196.

    1995

    • Whitby D, Howard MR, Tenant-Flowers M, Brink NS, Copas A, Boshoff C, Hatzioannou T, Suggett FE, Aldam DM, Denton AS (1995). Detection of Kaposi sarcoma associated herpesvirus in peripheral blood of HIV-infected individuals and progression to Kaposi's sarcoma.. Lancet, 346(8978), 799 - 802.

    • Walker K, Omar RZ, Copas AJ (). The effect of missing observations on parameter estimates and significance from clustered data in health studies..

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