Heath Heatlie

Siblings, multiple births, and the incidence of allergic disease: a birth cohort study using the West Midlands general practice research database

BACKGROUND The presence of older siblings reduces the risk of developing hay fever, eczema and atopy, but findings for asthma have been inconsistent. Whether twins have a reduced risk of allergic disease is also unclear. We have investigated these questions in a birth cohort analysis of the West Midlands General Practice Research Database (GPRD). METHODS Our birth cohort included 29 238 children. The incidence of allergic disease was examined according to the number of siblings, multiple births, and parental allergic disease and smoking habit using Cox regression. RESULTS There was a dose related decrease in the incidence of eczema and hay fever with increasing number of older siblings (hazard ratio for children with three or more older siblings compared with none 0.70 (95% CI 0.64 to 0.76) for eczema and 0.67 (95% CI 0.52 to 0.86) for hay fever). In contrast, the presence of older siblings increased the incidence of asthma (HR 1.17, 95% CI 1.06 to 1.29), although this effect was strongly dependent on age of diagnosis. For children diagnosed over the age of 2 years the presence of older siblings was protective (HR 0.66, 95% CI 0.52 to 0.82), while below this age the reverse was true (HR 1.38, 95% CI 1.24 to 1.54). Members of a multiple birth had a reduced incidence of all three allergic diseases. Birth order and multiple birth effects were independent of sex, maternal age, consulting behaviour, and parental allergy and smoking habit. CONCLUSIONS The presence of older siblings and being a member of a multiple birth appears to protect against the development of eczema, hay fever, and asthma diagnosed after the age of 2. In contrast, the presence of older siblings increases the incidence of early asthma.

Validating estimates of problematic drug use in England

BackgroundUK Government expenditure on combatting drug abuse is based on estimates of illicit drug users, yet the validity of these estimates is unknown. This study aims to assess the face validity of problematic drug use (PDU) and injecting drug use (IDU) estimates for all English Drug Action Teams (DATs) in 2001. The estimates were derived from a statistical model using the Multiple Indicator Method (MIM).MethodsQuestionnaire study, in which the 149 English Drug Action Teams were asked to evaluate the MIM estimates for their DAT.ResultsThe response rate was 60% and there were no indications of selection bias. Of responding DATs, 64% thought the PDU estimates were about right or did not dispute them, while 27% had estimates that were too low and 9% were too high. The figures for the IDU estimates were 52% (about right), 44% (too low) and 3% (too high).ConclusionThis is the first UK study to determine the validity estimates of problematic and injecting drug misuse. The results of this paper highlight the need to consider criterion and face validity when evaluating estimates of the number of drug users.

Ratio of Inhaled Corticosteroid to Bronchodilator Treatment and Asthma Hospitalisation

Summary Background: Previous research based on aggregated data has led to conflicting interpretations of the relationship between the corticosteroid:bronchodilator (C:B) ratio and outcome measures. Objectives: To assess whether the C:B ratio is associated with hospital contact for asthma at individual patient level. Methods: The study was a retrospective multivariate analysis, using data from the UK General Practice Research Database from 1993 to 1996. The subjects were 3465 asthma-diagnosed patients receiving bronchodilator and corticosteroid medication. The main outcome measures were asthma-related hospital contacts. Results: There was an inverse association between the C:B ratio and hospital contact after controlling for age. The odds ratio for the C:B ratio was 0.87 (95% CI 0.73–0.98) and 1.04 (95% CI 1.01–1.07) for five-year agebands among patients aged five years and over. There was no systematic relationship between the C:B ratio and hospital contacts for patients aged under five years. Conclusion: The results of this study show that higher C:B ratios are associated with lower levels of hospital contacts at patient level, although there are exceptions possibly linked to disease severity. For patients under five years, the ratio may not be a good outcome measure, perhaps owing to the difficulty in diagnosing asthma or poor compliance.

Defining the spectrum of appropriate prescribing: implications for effective medicines management

SummaryThe key objective of clinical governance in relationship to prescribing should be to optimise the use of the evidence base for medicines to ensure that cost issues do not over-ride the quality agenda and that health gain for patients remains the focus of the prescribing agenda. As most medicines are dispensed through primary care, a key consideration is the formation of primary care groups. Prescribing Analysis and Cost (PACT) data is currently the principal method, which enable practices to monitor their prescribing and assess various issues such as identification of therapeutic sections that account for the largest proportion of spending. However practices may be targeted for intervention on the basis of their PACT data although little is known about variation in disease prevalence or patient characteristics. Patient based systems such as the General Practice Research Database (GPRD) enable consideration of such factors. We illustrate how the GPRD has been used to show that prescribing of proton pump inhibitors for uncomplicated dyspepsia and non-specific abdominal symptoms, which were outside the licensed indications, accounted for 46% of new prescribing by 1995. If this ratio of new prescriptions is carried over into repeat prescriptions nearly a half of the current national annual expenditure of £247m could be for non-specific upper gastrointestinal symptoms. While there may be valid reasons for such prescribing, the GPRD enables a greater understanding of prescribing activity than is possible with routine prescribing data, because of the link to diagnosis and this may be relevant to other therapeutic areas. Within the next five to ten years there may be further developments centring on electronic data interchange (EDI) which will be patient based and comprise complete medication profiles. In summary, there is increasing scope for evaluating the spectrum of appropriate prescribing.