A total of 1.8 million visits are made to genitourinary medicine (GUM) clinics in the United Kingdom every year.1 Twenty-three per cent of Chlamydia trachomatis infection diagnoses in women in the United Kingdom are made in primary care.2 City and Hackney Primary Care Trust (CHPCT) in the east end of London has a young, ethnically diverse population3 with a high prevalence of sexually transmitted infections (STI).4 In April 2004 CHPCT developed a local-enhanced service facilitating the provision of sexual diagnosis and treatment within primary care.5 This included training, a local STI treatment guideline handbook, fast-track referral to the GUM clinic and employment of a general practitioner (GP) with a special interest in sexual health.

This study aims to outline the effects of establishing a local-enhanced service in sexual health and to compare the Primary Care Trust’s (PCT) costs for diagnosing STI in primary and secondary care.

METHODS

Specimens for the detection of C trachomatis and Neisseria gonorrhoea from venues within City and Hackney received by the pathology laboratory between 1 April 2002 and 31 March 2005 were identified from an electronic database.

Costing

For the purposes of the economic calculation, an STI test was defined as one specimen for C trachomatis PCR and one specimen for N gonorrhoea culture in both the GUM clinic and primary care. Other specimens were taken in both venues but are not included in the economic calculation. The cost of one chlamydia sample plus one gonorrhoea sample was £14.98 at all venues. At local-enhanced service participating surgeries, the PCT paid an annual retainer fee of £2000 and £150 per positive STI diagnosis. At the GUM clinic, the PCT pays £182 for a first visit and £104 for a follow-up visit (in those with an STI), according to the National Health Service reference costs for GUM appointments from 1 April 20066 with local adjustment.

The PCT cost per STI diagnosis in general practice was estimated as: [(£14.98 × number of STI tests) + (2000 × number of participating local-enhanced service surgeries) + (150 × number of STI diagnoses)]/[number of STI diagnoses].

The PCT cost per STI diagnosis in a GUM clinic was estimated as: [(£14.98 × number of STI tests) + (182 × number of first visits) + (104 × number of follow-up visits)]/[number of STI diagnoses].

Other STI such as non-specific urethritis, Trichomonas vaginalis, pelvic inflammatory disease, syphilis, viral hepatitis, genital warts, genital herpes, scabies, pediculosis pubis and HIV have been managed in both settings. These cases are easily identified from within the GUM clinic, although are less easy to confirm within primary care. For this reason, they have not been included in the economic analysis.

RESULTS

Thirty-two out of 51 general practices in City and Hackney joined the local-enhanced service covering 187 150 (71%) clients registered with a GP within CHPCT. The number of tests and diagnoses made are shown in table 1. GPs accounted for 15% of chlamydia tests performed in the borough in 2002 and 18% in 2004 (p<0.005, Fishers’ exact test). This upward trend predated the initiation of the local-enhanced service in April 2004. Despite this increase in testing, the number of cases of chlamydial and gonorrhoeal infection diagnosed in primary care remained relatively stable throughout the duration of the study.

There was an eightfold difference in the number of positive chlamydia diagnoses per 1000 practice population between local-enhanced service (0.8) and non-local-enhanced service GPs (0.1) (p<0.03). This difference predated the introduction of this local-enhanced service and continued as the local-enhanced service was introduced.

Individual local-enhanced service GPs showed considerable variation in the number of STI diagnosed, with the mean number of diagnoses made per surgery being 4.91 (range 0–17, SD 5.5). Ten of the local-enhanced service surgeries made no STI diagnoses, despite being paid the £2000 retainer fee.

In 2004, the cost per case of gonorrhoea or chlamydia diagnosed in general practice was £[(14.98 × 4166) + (32 × 2000) + (150 × 162)]/162  =  £930. The cost per case of gonorrhoea or chlamydia diagnosed in GUM clinics was £(14.98 × 12 811) + (182 × 12 811) + (104 × 1939)/1939  =  £1405. The GUM clinic diagnosed a further 2724 STI in 2004. If these are calculated, the cost per STI diagnosed at GUM clinics was £646. No comparable figure for the number of these infections diagnosed in primary care exists.

DISCUSSION

The number of chlamydia and gonorrhoea tests performed rose from 2002 to 2004 in CHPCT including at local-enhanced service GPs, whereas the number of chlamydia and gonorrhoea diagnoses remained relatively unchanged. local-enhanced service GPs accounted for 8% of chlamydial cases diagnosed within the borough in 2004, whereas surgeries that did not join the local-enhanced service accounted for 0.3% of the total number of STI diagnosed.

The need for a local-enhanced service in sexual health has been described by other authors7 but this is the first study describing the impact of a local-enhanced service for sexual health, while simultaneously revealing differences between local-enhanced service practices and non-local-enhanced service practices. It is an observational study. The data do not permit comment on the demographic profiles of the populations involved or the overlap between clients accessing both local-enhanced service GPs and the GUM clinic. It cannot comment on the impact the local-enhanced service had on the workload of the GUM clinic as a number of other factors contribute to this.

The results demonstrated an inequity in service provision within general practice predating the local-enhanced service. The wide disparity in the numbers of tests undertaken by different surgeries after the introduction of the local-enhanced service indicates that signing up to the local-enhanced service in itself did not encourage STI testing in primary care. The local-enhanced service did not directly add to the services provided by increasing STI diagnoses but may have offered support for primary care doctors wishing to test for and diagnose STI.

The cost to the PCT per case of gonorrhoeal or chlamydial infection diagnosed within the local-enhanced service was £930, whereas in the GUM clinic the cost was £1405. If all STI are included, the cost per STI diagnosed in the GUM clinic was £630. Comparison with other STI diagnosed in primary care was not possible, although it is highly plausible that far fewer STI other than chlamydia and gonorrhoea were diagnosed in primary care than the GUM clinic. Direct comparison of the diagnosis costs within general practice and at the GUM clinic is difficult as both provide services unavailable in the other. Therefore, we have focused on the costs for the PCT in each venue as opposed to a comprehensive health costs analysis.

The £2000 retainer fee added to the £930 cost per STI diagnosed by local-enhanced service GPs. The local-enhanced service costs are increased by the one-third of practices that received the retainer but made no STI diagnosis. The decision to pay per positive diagnosis, rather than per STI test, was unpopular with some GPs, but is supported by feedback from other PCT (H Wheeler, personal communication).8

As STI testing in primary care becomes more established, this service may evolve. The sexual health local-enhanced service may provide support for GPs wishing to diagnose and treat STI.