Irene Petersen

The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) Statement

Routinely collected health data, obtained for administrative and clinical purposes without specific a priori research goals, are increasingly used for research. The rapid evolution and availability of these data have revealed issues not addressed by existing reporting guidelines, such as Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). The REporting of studies Conducted using Observational Routinely collected health Data (RECORD) statement was created to fill these gaps. RECORD was created as an extension to the STROBE statement to address reporting items specific to observational studies using routinely collected health data. RECORD consists of a checklist of 13 items related to the title, abstract, introduction, methods, results, and discussion section of articles, and other information required for inclusion in such research reports. This document contains the checklist and explanatory and elaboration information to enhance the use of the checklist. Examples of good reporting for each RECORD checklist item are also included herein. This document, as well as the accompanying website and message board (http://www.record-statement.org), will enhance the implementation and understanding of RECORD. Through implementation of RECORD, authors, journals editors, and peer reviewers can encourage transparency of research reporting.

Protective effect of antibiotics against serious complications of common respiratory tract infections: retrospective cohort study with the UK General Practice Research Database

Objective To determine the extent to which antibiotics reduce the risk of serious complications after common respiratory tract infections. Design Retrospective cohort study. Setting UK primary care practices contributing to the general practice research database. Data source 3.36 million episodes of respiratory tract infection. Main outcome measures Risk of serious complications in treated and untreated patients in the month after diagnosis: mastoiditis after otitis media, quinsy after sore throat, and pneumonia after upper respiratory tract infection and chest infection. Number of patients needed to treat to prevent one complication. Results Serious complications were rare after upper respiratory tract infections, sore throat, and otitis media, and the number needed to treat was over 4000. The risk of pneumonia after chest infection was high, particularly in elderly people, and was substantially reduced by antibiotic use, with a number needed to treat of 39 for those aged ≥65 and 96-119 in younger age groups. Conclusion Antibiotics are not justified to reduce the risk of serious complications for upper respiratory tract infection, sore throat, or otitis media. Antibiotics substantially reduce the risk of pneumonia after chest infection, particularly in elderly people in whom the risk is highest.

Prediagnostic presentations of Parkinson's disease in primary care: a case-control study

BACKGROUND Parkinsons disease has an insidious onset and is diagnosed when typical motor features occur. Several motor and non-motor features can occur before diagnosis, early in the disease process. We aimed to assess the association between first presentation of several prediagnostic features in primary care and a subsequent diagnosis of Parkinsons disease, and to chart the timeline of these first presentations before diagnosis. METHODS We identified individuals with a first diagnosis of Parkinsons disease and those without Parkinsons disease from Jan 1, 1996, to Dec 31, 2012, from The Health Improvement Network UK primary care database. Codes were extracted for a range of possible prediagnostic or early symptoms, comprising motor features (tremor, rigidity, balance impairments, neck pain or stiffness, and shoulder pain or stiffness), autonomic features (constipation, hypotension, erectile dysfunction, urinary dysfunction, and dizziness), neuropsychiatric disturbances (memory problems, late-onset anxiety or depression, cognitive decline, and apathy), and additional features (fatigue, insomnia, anosmia, hypersalivation and rapid-eye-movement sleep behaviour disorder) in the years before diagnosis. We report the incidence of symptoms recorded in more than 1% of cases per 1000 person-years and incidence risk ratios (RRs) for individuals with and without Parkinsons disease at 2, 5, and 10 years before diagnosis. FINDINGS 8166 individuals with and 46,755 individuals without Parkinsons disease were included in the study. Apathy, REM sleep behaviour disorder, anosmia, hypersalivation, and cognitive decline were all reported in less than 1% of people per 1000 person-years and were excluded from further analyses. At 2 years before Parkinsons disease diagnosis, the incidence of all studied prediagnostic features except neck pain or stiffness was higher in patients who went on to develop Parkinsons disease (n=7232) than in controls (n=40,541). At 5 years before diagnosis, compared with controls (n=25,544), patients who went on to develop Parkinsons disease (n=4769) had a higher incidence of tremor (RR 13·70, 95% CI 7·82-24·31), balance impairments (2·19, 1·09-4·16), constipation (2·24, 2·04-2·46), hypotension (3·23, 1·85-5·52), erectile dysfunction (1·30, 1·11-1·51), urinary dysfunction (1·96, 1·34-2·80), dizziness (1·99, 1·67-2·37), fatigue (1·56, 1·27-1·91), depression (1·76, 1·41-2·17), and anxiety (1·41, 1·09-1·79). At 10 years before diagnosis of Parkinsons disease, the incidence of tremor (RR 7·59, 95% CI 1·11-44·83) and constipation (2·01, 1·62-2·49) was higher in those who went on to develop Parkinsons disease (n=1680) than in controls (n=8305). INTERPRETATION A range of prediagnostic features can be detected several years before diagnosis of Parkinsons disease in primary care. These data can be incorporated into ongoing efforts to identify individuals at the earliest stages of the disease for inclusion in future trials and to help understand progression in the earliest phase of Parkinsons disease. FUNDING Parkinsons UK.

Survival of people with clinical diagnosis of dementia in primary care: cohort study

Objectives To estimate survival after a diagnosis of dementia in primary care, compared with people without dementia, and to determine incidence of dementia. Design Cohort study using data from The Health Improvement Network (THIN), a primary care database. Setting 353 general practices in the United Kingdom providing data to THIN. Participants All adults aged 60 years or over with a first ever code for dementia from 1990 to 2007 (n=22 529); random sample of five participants without dementia for every participant with dementia matched on practice and time period (n=112 645). Main outcome measures Median survival by age and sex; mortality rates; incidence of dementia by age, sex, and deprivation. Results The median survival of people with dementia diagnosed at age 60-69 was 6.7 (interquartile range 3.1-10.8) years, falling to 1.9 (0.7-3.6) years for those diagnosed at age 90 or over. Adjusted mortality rates were highest in the first year after diagnosis (relative risk 3.68, 95% confidence interval 3.44 to 3.94). This dropped to 2.49 (2.29 to 2.71) in the second year. The incidence of recorded dementia remained stable over time (3-4/1000 person years at risk). The incidence was higher in women and in younger age groups (60-79 years) living in deprived areas. Conclusions Median survival was much lower than in screened populations. These clinically relevant estimates can assist patients and carers, clinicians, and policy makers when planning support for this population. The high risk of death in the first year after diagnosis may reflect diagnoses made at times of crisis or late in the disease trajectory. Late recording of diagnoses of dementia in primary care may result in missed opportunities for potential early interventions.

The incidence of eating disorders in the UK in 2000–2009: findings from the General Practice Research Database

Objectives Few studies have investigated the incidence of eating disorders (EDs). Important questions about changes in the incidence of diagnosed disorders in recent years, disorder and gender-specific onset and case detection remain unanswered. Understanding changes in incidence is important for public health, clinical practice and service provision. The aim of this study was to estimate the annual (age-specific, gender-specific and subtype-specific) incidence of diagnosed ED: anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified (EDNOS) in primary care over a 10-year period in the UK (2000–2009); to examine the changes within the study period; and to describe peak age at diagnosis. Design Register-based study. Setting Primary care. Data were obtained from a primary care register, the General Practice Research Database, which contains anonymised records representing about 5% of the UK population. Participants All patients with a first-time diagnosis of AN, BN and EDNOS were identified. Primary outcome Annual crude and age-standardised incidence rates were calculated. Results A total of 9072 patients with a first-time diagnosis of an ED were identified. The age-standardised annual incidence rate of all diagnosed ED for ages 10–49 increased from 32.3 (95% CI 31.7 to 32.9) to 37.2 (95% CI 36.6 to 37.9) per 100 000 between 2000 and 2009. The incidence of AN and BN was stable; however, the incidence of EDNOS increased. The incidence of the diagnosed ED was highest for girls aged 15–19 and for boys aged 10–14. Conclusions The age-standardised incidence of ED increased in primary care between 2000 and 2009. New diagnoses of EDNOS increased, and EDNOS is the most common ED in primary care.

Guillain-Barré Syndrome and Preceding Infection with Campylobacter, Influenza and Epstein-Barr Virus in the General Practice Research Database

Background A number of infectious agents have previously been suggested as risk factors for the development of Guillain-Barré syndrome (GBS), but robust epidemiologic evidence for these associations is lacking. Methods and Findings We conducted a nested case-control study using data from the United Kingdom General Practice Research Database between 1991 and 2001. Controls were matched to cases on general practice clinic, sex, year of birth and date of outcome diagnosis in their matched case. We found positive associations between GBS and infection with Campylobacter, Epstein-Barr virus and influenza-like illness in the previous two months, as well as evidence of a protective effect of influenza vaccination. After correction for under-ascertainment of Campylobacter infection, the excess risk of GBS following Campylobacter enteritis was 60-fold and 20% of GBS cases were attributable to this pathogen. Conclusions Our findings indicate a far greater excess risk of GBS among Campylobacter enteritis patients than previously reported by retrospective serological studies. In addition, they confirm previously suggested associations between infection due to Epstein-Barr virus infection and influenza-like illness and GBS. Finally, we report evidence of a protective effect of influenza vaccination on GBS risk, which may be mediated through protection against influenza disease, or result from a lower likelihood of vaccination among those with recent infection. Cohort studies of GBS incidence in this population would help to clarify the burden of GBS due to influenza, and any potential protective effect of influenza vaccination.

Do men consult less than women? An analysis of routinely collected UK general practice data

Objective To examine whether gender differences in primary care consultation rates (1) vary by age and deprivation status and (2) diminish when consultation for reproductive reasons or common underlying morbidities are accounted for. Design Cross-sectional study of a cohort of patients registered with general practice. Setting UK primary care. Subjects Patients (1 869 149 men and 1 916 898 women) registered with 446 eligible practices in 2010. Primary outcome measures Primary care consultation rate. Results This study analyses routinely collected primary care consultation data. The crude consultation rate was 32% lower in men than women. The magnitude of gender difference varied across the life course, and there was no ‘excess’ female consulting in early and later life. The greatest gender gap in primary care consultations was seen among those aged between 16 and 60 years. Gender differences in consulting were higher in people from more deprived areas than among those from more affluent areas. Accounting for reproductive-related consultations diminished but did not eradicate the gender gap. However, consultation rates in men and women who had comparable underlying morbidities (as assessed by receipt of medication) were similar; men in receipt of antidepressant medication were only 8% less likely to consult than women in receipt of antidepressant medication (relative risk (RR) 0.916, 95% CI 0.913 to 0.918), and men in receipt of medication to treat cardiovascular disease were just 5% less likely to consult (RR=0.950, 95% CI 0.948 to 0.952) than women receiving similar medication. These small gender differences diminished further, particularly for depression (RR=0.950, 95% CI 0.947 to 0.953), after also taking account of reproductive consultations. Conclusions Overall gender differences in consulting are most marked between the ages of 16 and 60 years; these differences are only partially accounted for by consultations for reproductive reasons. Differences in consultation rates between men and women were largely eradicated when comparing men and women in receipt of medication for similar underlying morbidities.

Serum Bilirubin and Risk of Respiratory Disease and Death

CONTEXT Serum total bilirubin levels in healthy patients reflect genetic and environmental factors that could influence the risk of developing respiratory disease. OBJECTIVE To examine the relationship between bilirubin levels and respiratory disease. DESIGN, SETTING, AND PARTICIPANTS Cohort study among 504,206 adults from a UK primary care research database (the Health Improvement Network) with serum bilirubin levels recorded but no evidence of hepatobiliary or hemolytic disease. Data were recorded between January 1988 and December 2008. MAIN OUTCOME MEASURES Incidence of chronic obstructive pulmonary disease (COPD), lung cancer, and all-cause mortality. RESULTS Median bilirubin levels were 0.64 mg/dL (interquartile range, 0.47-0.88 mg/dL) in men and 0.53 mg/dL (interquartile range, 0.41-0.70 mg/dL) in women. There were 1341 cases of lung cancer, 5863 cases of COPD, and 23,103 deaths, with incidence rates of 2.5, 11.9, and 42.5 per 10,000 person-years, respectively. The incidence of lung cancer per 10,000 person-years in men was 5.0 (95% confidence interval [CI], 4.2-6.0) in the first decile category of bilirubin compared with 3.0 (95% CI, 2.3-3.8) in the fifth decile. The corresponding incidences for COPD in men were 19.5 (95% CI,17.7-21.4) and 14.4 (95% CI, 12.7-16.2). The mortality rates per 10,000 person-years in men were 51.3 (95% CI, 48.5-54.2) in the first decile category compared with 38.1 (95% CI, 35.5-40.8) in the fifth decile. The associations were similar for women. After adjusting for other important health indicators, regression estimates for incidence rate of lung cancer per 0.1-mg/dL increase in bilirubin level were an 8% decrease (95% CI, 5%-11%) for men and an 11% decrease (95% CI, 7%-14%) for women. The regression estimate for COPD in men per 0.1-mg/dL increase in bilirubin level was a 6% decrease (95% CI, 5%-7%) and for mortality in men was a 3% decrease (95% CI, 2%-3%) after accounting for other health indicators. The results for COPD and mortality in women were very similar. CONCLUSION Among patients with normal-range bilirubin levels in primary care practices, relatively higher levels of bilirubin were associated with a lower risk of respiratory disease and all-cause mortality.

Creating medical and drug code lists to identify cases in primary care databases

This paper demonstrates how compilation of medical and drug code lists for outcomes or exposures of interest for studies using primary care databases can be carried out efficiently using Stata. Use of Stata do‐files to record and execute the commands provides good documentation and ease of replication of the procedure. Copyright

Recent trends in the incidence of recorded depression in primary care

BACKGROUND There is a paucity of data describing how general practitioners (GPs) label or record depression. AIMS To determine incidence and sociodemographic variation in GP-recorded depression diagnoses and depressive symptoms. METHOD Annual incidence rates calculated using data from 298 UK general practices between 1996 and 2006, adjusted for year of diagnosis, gender, age and deprivation. RESULTS Incidence of diagnosed depression fell from 22.5 to 14.0 per 1000 person-years at risk (PYAR) from 1996 to 2006. The incidence of depressive symptoms rose threefold from 5.1 to 15.5 per 1000 PYAR. Combined incidence of diagnoses and symptoms remained stable. Diagnosed depression and symptoms were more common in women and in more deprived areas. CONCLUSIONS Depression recorded by general practitioners has lower incidence rates than depression recorded in epidemiological studies, although there are similar associations with gender and deprivation. General practitioners increasingly use symptoms rather than diagnostic labels to categorize peoples illnesses. Studies using standardised diagnostic instruments may not be easily comparable with clinical practice.