Cross sectional survey.

All 826 general practices in Trent region in existence between 1994 and 1997.

All pregnancies of teenagers aged 13 to 19 between 1994 and 1997 that resulted in an admission to an NHS hospital.

Pregnancy rates for teenagers aged 13 to 19 and general practice characteristics: presence of a female or young doctor (under 36 years old), number of whole time equivalent practice nurses, Townsend score, vocational training status, list size per whole time equivalent doctor, fundholding status, and partnership size.

On multivariate analysis, lower teenage pregnancy rates were associated with the presence of a female or young doctor and more nurse time. Practices in deprived areas had higher teenage pregnancy rates.

Patients were included if they were aged 19 or under at the time of the pregnancy related hospital admission and registered with a doctor in Trent region. Patients from Humberside were not included as Humberside had not been part of Trent for the whole study period. It was assumed that admissions with the same date of birth and the same postcode arising within the same six week period related to the same pregnancy, and duplicate entries were removed.

In 1997 there were 826 general practices in Trent, of which 627 (75%) were wholly, predominantly, or mainly urban according to Carstairs' categories.¹² The study practices (table ​(table1)1) had similar characteristics to other practices in England and Wales. For example, 350 practices (42.4% of 826) did not have a female doctor, which is comparable to the national figure of 41.7%.

Lower incidence rate ratios (lower teenage pregnancy rates) were associated with more nurse time or female or young doctors (table ​(table2).2). A young doctor (under 36 years) was defined as a doctor in the lowest quartile for age calculated from the ages of all the general practitioners in Trent for whom we had data. Higher teenage pregnancy rates were significantly associated with increasing deprivation scores and fundholding status.

On multivariate analysis, practices with at least one female doctor, a young doctor, or more practice nurse time had significantly lower teenage pregnancy rates (table ​(table3).3). Deprivation and fundholding remained significantly associated with higher teenage pregnancy rates.

The distance (km) from each surgery to the nearest family planning clinic was included in the multivariate analysis, adjusting for each of the variables listed in table ​table2.2. Overall, practices that were far from family planning clinics had lower teenage pregnancy rates (adjusted incidence rate ratio 0.98, 95% confidence interval 0.97 to 0.99; P=0.001). This was mainly due to the effect of rurality since rural practices were far from family planning clinics and had lower rates (0.98, 0.97 to 0.99; P=0.003). In urban practices there was no association between teenage pregnancy rates and distance from family planning clinics (1.01, 0.99 to 1.02; P=0.15).

We repeated the analyses including the number of miscarriages in the total number of pregnancies per practice. We found no substantial changes in the direction or significance of any of the variables.

Several methodological issues need consideration. Firstly, multiple regression analyses of general practice and sociodemographic data can help to explain variations and unravel complex associations. A causal relation, however, cannot be inferred from a statistical association, particularly in a cross sectional study. Secondly, we have used routinely collected NHS data for our study, which may be limited in terms of accuracy and completeness.¹⁵ We did, however, include two checks for data quality that were reassuring. We were not able to include private terminations as the data were not available at practice level. This may have confounded the results as the proportion of private referrals per practice may be affected by deprivation. Similarly the results may have been confounded by the provision and uptake of school based contraceptive services. Thirdly, we have been unable to identify teenagers with repeat pregnancies in the study period. Repeat pregnancies would have resulted in an underestimate of the standard error. It would not have affected the rate ratio but would have made the results seem unduly significant. As our significance levels were, however, less than 0.001, it is unlikely to have affected our main conclusions. We repeated the analysis for each of the three years of data, since there is less chance of multiple pregnancies occurring to an individual within the same year. The results of the key univariate and multivariate analyses remained unchanged. Strengths of our study include its sample size and duration of sampling.

General practices with a female partner have lower teenage pregnancy rates than those without a female partner. As our study was cross sectional, we do not know whether female doctors had chosen to work in areas with low teenage pregnancy rates or whether the presence of a female doctor influenced such rates. The association between low teenage pregnancy rate and the presence of a female doctor may be because female doctors tend to have longer consultations and handle more problems per consultation¹⁶ and tend to be more communicative¹⁷ and more patient centered.¹⁸ Female doctors report less difficulty in discussing sexual problems with teenagers and are more likely to provide information about the prevention of sexually transmitted diseases^19,20 and the use of condoms.²¹ Our findings might be due to differences in case mix between practices with and without a female doctor since patients presenting to female doctors tend to be younger, more often female,¹⁶ and more likely to have female specific problems than those presenting to practices without a female doctor.

Practices with a young doctor have lower teenage pregnancy rates than those without a young doctor. Although younger doctors may be more interested in teenage health issues, little is known about the effect of the age of the doctor on provision of teenage contraceptive services. Younger doctors tend to have higher rates for smear uptake and immunisation²² and order more infertility investigations.²³

Practices with more practice nurse time had significantly lower teenage pregnancy rates than those with less practice nurse time. Since 10% of all practice nurse consultations are with teenagers²⁴ and up to 3% of all nurse consultations are for contraceptive advice, there may be scope for further developing the practice nurse's role in the delivery of contraceptive services to teenagers. We are unable to explain the association between fundholding and higher teenage pregnancy rates.