Research

Trends in sexually transmitted infections in general practice 1990-2000: population based study using data from the UK general practice research database

BMJ 2006; 332 doi: http://dx.doi.org/10.1136/bmj.38726.404120.7C (Published 09 February 2006) Cite this as: BMJ 2006;332:332
  1. Jackie A Cassell, senior clinical research fellow (j.cassell{at}pcps.ucl.ac.uk)1,
  2. Catherine H Mercer, research fellow2,
  3. Lorna Sutcliffe, research coordinator1,
  4. Irene Petersen, research fellow1,
  5. Amir Islam, research fellow1,
  6. M Gary Brook, consultant genitourinary physician3,
  7. Jonathan D Ross, consultant genitourinary physician4,
  8. George R Kinghorn, consultant genitourinary physician5,
  9. Ian Simms, senior epidemiological scientist6,
  10. Gwenda Hughes, head of research services7,
  11. Azeem Majeed, professor of primary care and social medicine1,
  12. Judith M Stephenson, reader in epidemiology2,
  13. Anne M Johnson, professor of epidemiology1,
  14. Andrew C Hayward, senior lecturer in infectious disease epidemiology1
  1. 1 Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London NW3 3PF
  2. 2 Centre for Sexual Health and HIV Research, Royal Free and University College Medical School, London WC1E 6AU
  3. 3 Patrick Clements Clinic, Central Middlesex Hospital, London NW10 7NS
  4. 4 Whittall Street Clinic, Birmingham B4 6DH
  5. 5 Royal Hallamshire Hospital, Sheffield S10 2JF
  6. 6 Centre for Infections (Communicable Disease Surveillance Centre), Health Protection Agency, London NW9 5EQ
  7. 7 General Practice Research Database Division, Medicines and Healthcare Regulatory Agency, London SW8 5NQ
  1. Correspondence to: J A Cassell
  • Accepted 17 November 2005

Abstract

Objective To describe the contribution of primary care to the diagnosis and management of sexually transmitted infections in the United Kingdom, 1990-2000, in the context of increasing incidence of infections in genitourinary medicine clinics.

Design Population based study.

Setting UK primary care.

Participants Patients registered in the UK general practice research database.

Main outcome measures Incidence of diagnosed sexually transmitted infections in primary care and estimation of the proportion of major such infections diagnosed in primary care.

Results An estimated 23.0% of chlamydia cases in women but only 5.3% in men were diagnosed and treated in primary care during 1998-2000, along with 49.2% cases of non-specific urethritis and urethral discharge in men and 5.7% cases of gonorrhoea in women and 2.9% in men. Rates of diagnosis in primary care rose substantially in the late 1990s.

Conclusions A substantial and increasing number of sexually transmitted infections are diagnosed and treated in primary care in the United Kingdom, with sex ratios differing from those in genitourinary medicine clinics. Large numbers of men are treated in primary care for presumptive sexually transmitted infections.

Introduction

Diagnoses of sexually transmitted infections from UK genitourinary medicine clinics have increased considerably since the mid-1990s.1 The national strategy for sexual health proposed a shift of services for sexually transmitted infections to primary care in England.2 Yet little is known about the contribution of general practice to the diagnosis and management of sexually transmitted infections. It has been reported that 16% of men and 36% of women diagnosed as having chlamydia in the five years to 2000 were last treated in general practice.3 We analysed an anonymised primary care database to explore the contribution of general practice to the diagnosis and management of sexually transmitted infections in the United Kingdom.

Methods

We estimated the incidence of diagnosed sexually transmitted infections between 1990 and 2000 using a retrospective cohort of patients registered in the UK general practice research database, and surveillance data from genitourinary medicine clinics.4 The general practice research database contains the records of about 8 million patients, contributing 36 million patient years of observation. Diagnoses in general practice were based on READ or Oxmis codes and in the genitourinary medicine clinics on published KC60 diagnoses. We estimated the incidence of diagnosed sexually transmitted infections in general practice and calculated the proportion of major sexually transmitted infections that were diagnosed in this setting.

To minimise double counting of patients diagnosed in primary care but treated elsewhere, we distinguished patients who were diagnosed and treated in general practice from those who were not treated and therefore may have been referred elsewhere. We reviewed individual patient records when a diagnosis of chlamydia, gonorrhoea, trichomonas, or non-specific urethritis or urethral discharge was recorded during 1998-2000. We estimated sexually transmitted infections diagnosed in general practice separately from those diagnosed and treated in general practice. It was assumed that all patients diagnosed in a genitourinary medicine clinic were treated there. We then compared the incidence of sexually transmitted infections diagnosed and treated in general practice with the incidence of selected sexually transmitted infections diagnosed in genitourinary medicine clinics in the United Kingdom during 1998-2000.

Results

The percentage increase in sexually transmitted infections diagnosed in primary care during 1990-2000 was greatest for genital chlamydia (1253% in men, 2495% in women) and consistent with the increases found in genitourinary medicine clinics (table).5

Incidence of selected sexually transmitted infections diagnosed and treated in general practice and in genitourinary medicine clinics, 1998-2000, by sex

View this table:

Among incident cases recorded in general practice, evidence existed of treatment for 58.4% cases of chlamydia, 97.4% cases of non-specific urethritis or urethral discharge, and 46.2% cases of gonorrhoea. A large number of men with urethral discharge seem to be treated syndromically (without a microbiological diagnosis) in general practice, using antibiotics appropriate for non-specific urethritis. The age distribution of urethral discharge was similar to that of non-specific urethritis and chlamydia in men, with a peak in the 20-24 year old age group typical of the epidemiology of sexually transmitted infections in men.1 The incidence of chlamydia and gonorrhoea in women in general practice peaked in the 16-19 year old age group, as in genitourinary medicine clinics.

The sex ratio of most diagnoses of sexually transmitted infections differed between general practice and genitourinary medicine clinics. The men:women ratio for treated chlamydia was 0.77:1 in genitourinary medicine clinics compared with 0.14:1 in general practice, whereas the respective ratios for treated gonorrhoea were 2.27:1 and 1.12:1 and for genital herpes were 0.75:1 and 0.34:1

Discussion

A substantial and increasing number of sexually transmitted infections are diagnosed and treated in general practice and may reflect increasing engagement of general practitioners with sexual health. Rates of diagnosed sexually transmitted infections in the United Kingdom are higher than those captured by current surveillance based only on genitourinary medicine clinics.5 Significant numbers of men are treated in general practice for symptoms suggestive of sexually transmitted infections.

What is already known on this topic

Current surveillance of sexually transmitted infections based on genitourinary medicine clinics underestimates the burden of disease

What this study adds

The diagnosed incidence of sexually transmitted infections in the United Kingdom is higher than previously thought, with an increasing contribution from general practice

Men are commonly treated syndromically, and the sex ratios of diagnoses in general practice differ substantially from those in genitourinary medicine clinics

This article was posted on bmj.com on 26 January 2006: http://bmj.com/cgi/doi/10.1136/bmj.38726.404120.7C

Footnotes

  • Contributors JAC had the original idea for the study and obtained funding. JAC, CHM, LS, AMJ, IP, AI, AM, MGB, JDR, JS, GRK, IS, and GH planned the strategy for analysis of the data. All authors reviewed the codes, further developed the analytic strategy, and drafted and revised the paper. IP and AI led the data extraction. The work was discussed and developed through departmental research seminars, to which all authors and numerous unnamed others contributed. JAC and CHM are guarantors. The views expressed are those of the authors and not necessarily those of the Medical Research Council or the health departments.

  • Funding This study was funded by the Medical Research Council, with funding allocated from the health departments under the aegis of the Medical Research Council and UK health departments Sexual Health and HIV Research Strategy Committee.

  • Competing interests None declared.

  • Ethical approval Scientific and Ethical Advisory Group of the general practice research database.

References

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