Publications
scientifiques

OBJECTIVES: In the context of women's health, we examine (1) the role that observational ('real-world') studies have in overcoming limitations of randomised clinical trials, (2) the relative advantages and disadvantages of different study designs, (3) the importance of outcome data from observational studies when making health-economic or clinical decisions, and (4) provide insights into changing perceptions of observational clinical data. METHODS: PubMed and internet searches were used to identify (i) guidance and expert commentary on designing, conducting, analysing, and reporting clinical trials or observational studies, (ii) supporting evidence of the rapid growth of observational ('real world') studies and publications since the turn of millennium in the fields of contraception, reproductive health, obstetrics or gynaecology. RESULTS: The rapidly growing use and validation of large, computerised medical records and related databases (e.g., health insurance or national registries) have played a major part in changing perceptions of observational data among researchers and clinicians. In the past 10 years, a distinct increase in the number of observational studies published tends to confirm their growing acceptance, appreciation and use. CONCLUSIONS: Observational studies can provide information that is impossible or infeasible to obtain otherwise (e.g., impractical, very expensive, or ethically unacceptable). Greater understanding, dissemination, uptake and use of observational data might be expected to drive ongoing evolution of research, data collection, analysis, and validation, in turn improving quality and therefore credibility, utility, and further application by clinicians.

OBJECTIVES: To measure the incidence of movement side effects of antipsychotic drugs in adults with intellectual disability and compare rates with adults without intellectual disability. DESIGN: Cohort study using data from The Health Improvement Network. SETTING: UK primary care. PARTICIPANTS: Adults with intellectual disability prescribed antipsychotic drugs matched to a control group of adults without intellectual disability prescribed antipsychotic drugs. OUTCOME MEASURES: New records of movement side effect including acute dystonias, akathisia, parkinsonism, tardive dyskinaesia and neuroleptic malignant syndrome. RESULTS: 9013 adults with intellectual disability and a control cohort of 34 242 adults without intellectual disability together contributed 148 709 person-years data. The overall incidence of recorded movement side effects was 275 per 10 000 person-years (95% CI 256 to 296) in the intellectual disability group and 248 per 10 000 person-years (95% CI 237 to 260) in the control group. The incidence of any recorded movement side effect was significantly greater in people with intellectual disability compared with those without (incidence rate ratio 1.30, 95% CI 1.18 to 1.42, p<0.001, after adjustment for potential confounders), with parkinsonism and akathisia showing the greatest difference between the groups. Neuroleptic malignant syndrome, although occurring infrequently, was three times more common in people with intellectual disability-prescribed antipsychotic drugs (incidence rate ratio 3.03, 95% CI 1.26 to 7.30, p=0.013). Differences in rates of movement side effects between the groups were not due to differences in the proportions prescribed first and second-generation antipsychotic drugs. CONCLUSIONS: This study provides evidence to substantiate the long-held assumption that people with intellectual disability are more susceptible to movement side effects of antipsychotic drugs. Assessment for movement side effects should be integral to antipsychotic drug monitoring in people with intellectual disability. Regular medication review is essential to ensure optimal prescribing in this group.

AIM: Statins may increase the risk of new-onset diabetes and adversely affect glycaemic control, but their effects on the glycemic response and mortality outcomes following commencement of insulin therapy in patients with Type 2 Diabetes (T2D) are unclear. METHODS: A retrospective cohort study was conducted in 12,725 insulin initiators with T2D using The Health Improvement Network (THIN) UK database. Changes in HbA1c at 6, 12, 24 and 36 months, and the 5-year risk of mortality and (3-point) major adverse cardiovascular events (MACE), were compared between prior users (n = 10,682) and non-users (n = 2043) of statin therapy who were newly commenced on insulin treatment. Cox proportional hazard models were used to estimate the hazard ratios of the different outcomes. RESULTS: Mean age of the cohort was 58.7 ± 14.0 years (51% male) and mean baseline HbA1c was 8.7 ± 1.8%. A greater initial reduction in HbA1c was observed following insulin initiation in the non-users of statins compared with the users, which was significant in the short term (-0.34% vs -0.26% at 6 months; mean diff = -0.09%, p = 0.004) but not in the long term: -0.31% versus -0.35% at 3 years (mean diff = 0.05%, p = 0.344). CV events (3-point MACE) were 878 versus 217 in statin users versus non-users (20.7 vs 30.9 per 1000 person-years; adjusted Hazard Ratio (aHR) 1.36 (95% CI 1.15-1.62; p < 0.0001). In a subgroup analysis of individual statins, HbA1c was higher throughout the study duration with all statins relative to non-users of statin therapy (p < 0.05). The aHRs for 3-point MACE for atorvastatin, simvastatin, rosuvastatin and pravastatin were 0.82 (95% CI 0.68-0.98), 0.67 (0.55-0.82), 0.56 (0.39-0.81) and 0.78 (0.60-1.01), respectively. CONCLUSIONS: Following initiation of insulin therapy in patients with T2D in routine care, concurrent use of a statin was associated with less good glycaemic control in the short-term but a much lower risk of major adverse CV events.

Electronic health records hold great promise for clinical and epidemiologic research. Undertaking atopic eczema (AE) research using such data is challenging because of its episodic and heterogeneous nature. We sought to develop and validate a diagnostic algorithm that identifies AE cases based on codes used for electronic records used in the UK Health Improvement Network. We found that at least one of five diagnosis codes plus two treatment codes for any skin-directed therapy were likely to accurately identify patients with AE. To validate this algorithm, a questionnaire was sent to the physicians of 200 randomly selected children and adults. The primary outcome, positive predictive value for a physician-confirmed diagnosis of AE, was 86% (95% confidence interval = 80-91). Additional criteria increased the PPV up to 95% but would miss up to 89% of individuals with physician-confirmed AE. The first and last entered diagnosis codes for individuals showed good agreement with the physician-confirmed age at onset and last disease activity; the mean difference was 0.8 years (95% confidence interval = -0.3 to 1.9) and -1.3 years (95% confidence interval = -2.5 to -0.1), respectively. A combination of diagnostic and prescription codes can be used to reliably estimate the diagnosis and duration of AE from The Health Improvement Network primary care electronic health records in the UK.