Medical Record Databases

The UK-based General Practice Research Database (GPRD) is a valuable source of longitudinal primary care records and is increasingly used for epidemiological research. To conduct a systematic review of the literature on accuracy and completeness of diagnostic coding in the GPRD. Systematic review. Six electronic databases were searched using search terms relating to the GPRD, in association with terms synonymous with validity, accuracy, concordance, and recording. A positive predictive value was calculated for each diagnosis that considered a comparison with a gold standard. Studies were also considered that compared the GPRD with other databases and national statistics. A total of 49 papers are included in this review. Forty papers conducted validation of a clinical diagnosis in the GPRD. When assessed against a gold standard (validation using GP questionnaire, primary care medical records, or hospital correspondence), most of the diagnoses were accurately recorded in the patient electronic record. Acute conditions were not as well recorded, with positive predictive values lower than 50%. Twelve papers compared prevalence or consultation rates in the GPRD against other primary care databases or national statistics. Generally, there was good agreement between disease prevalence and consultation rates between the GPRD and other datasets; however, rates of diabetes and musculoskeletal conditions were underestimated in the GPRD. Most of the diagnoses coded in the GPRD are well recorded. Researchers using the GPRD may want to consider how well the disease of interest is recorded before planning research, and consider how to optimise the identification of clinical events.

Previous studies suggest that patients hospitalized for psoriasis have an increased frequency of a variety of cardiovascular comorbidities. Limited population-based data exist on this association, and few studies have determined which factors are independently associated with psoriasis. We sought to determine whether the prevalence of the major cardiovascular risk factors was higher in mild and severe psoriasis than in patients without psoriasis. We conducted a population-based study in the United Kingdom using the General Practice Research Database. Patients were classified as having severe psoriasis if they received a code for psoriasis as well as systemic therapy. Patients were defined as having mild psoriasis if they ever received a psoriasis code but no systemic therapy. Control subjects were selected from the same practices and start dates as psoriasis patients. Patients were classified as having risk factors if they received codes for diabetes, hypertension, hyperlipidemia, obesity, or smoking. Analyses were performed by using conditional logistic regression, and adjustments were made considering age, gender, person-years, and all cardiovascular risk factors. We identified 127,706 patients with mild psoriasis and 3854 with severe psoriasis. Respective prevalence rates of risk factors in those with severe psoriasis, mild psoriasis, and in controls were as follows: diabetes (7.1%, 4.4%, 3.3%), hypertension (20%, 14.7%, 11.9%), hyperlipidemia (6%, 4.7%, 3.3%), obesity (20.7%, 15.8%, 13.2%), and smoking (30.1%, 28%, 21.3%). Patients with mild psoriasis had a higher adjusted odds of diabetes (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.08-1.18]), hypertension (OR, 1.03; 95% CI, 1.01-1.06), hyperlipidemia (OR, 1.16; 95% CI, 1.12-1.21), obesity (OR, 1.27; 95% CI, 1.24-1.31), and smoking (OR, 1.31; 95% CI, 1.29-1.34) than controls. Patients with severe psoriasis had a higher adjusted odds of diabetes (OR, 1.62; 95% CI, 1.3-2.01), obesity (OR, 1.79; 95% CI, 1.55-2.05), and smoking (OR, 1.31; 95% CI, 1.17-1.47) than controls. Additionally, diabetes (OR, 1.39; 95% CI, 1.22-1.58) and obesity (OR, 1.47; 95% CI, 1.32-1.63) were more prevalent in those with severe psoriasis than with mild psoriasis. The study was cross-sectional and therefore the directionality of the associations could not be determined. Multiple cardiovascular risk factors are associated with psoriasis. Cardiovascular risk factors that are key components of the metabolic syndrome are more strongly associated with severe psoriasis than with mild psoriasis.

In 2004, after a series of national initiatives associated with marked improvements in the quality of care, the National Health Service of the United Kingdom introduced a pay-for-performance contract for family practitioners. This contract increases existing income according to performance with respect to 146 quality indicators covering clinical care for 10 chronic diseases, organization of care, and patient experience. We analyzed data extracted automatically from clinical computing systems for 8105 family practices in England in the first year of the pay-for-performance program (April 2004 through March 2005), data from the U.K. Census, and data on characteristics of individual family practices. We examined the proportion of patients deemed eligible for a clinical quality indicator for whom the indicator was met (reported achievement) and the proportion of the total number of patients with a medical condition for whom a quality indicator was met (population achievement), and we used multiple regression analysis to determine the extent to which practices achieved high scores by classifying patients as ineligible for quality indicators (exception reporting). The median reported achievement in the first year of the new contract was 83.4 percent (interquartile range, 78.2 to 87.0 percent). Sociodemographic characteristics of the patients (age and socioeconomic features) and practices (size of practice, number of patients per practitioner, age of practitioner, and whether the practitioner was medically educated in the United Kingdom) had moderate but significant effects on performance. Exception reporting by practices was not extensive (median rate, 6 percent), but it was the strongest predictor of achievement: a 1 percent increase in the rate of exception reporting was associated with a 0.31 percent increase in reported achievement. Exception reporting was high in a small number of practices: 1 percent of practices excluded more than 15 percent of patients. English family practices attained high levels of achievement in the first year of the new pay-for-performance contract. A small number of practices appear to have achieved high scores by excluding large numbers of patients by exception reporting. More research is needed to determine whether these practices are excluding patients for sound clinical reasons or in order to increase income. Copyright 2006 Massachusetts Medical Society.