Dataset Information

Validation of asthma recording in the Clinical Practice Research Datalink (CPRD).

ABSTRACT: OBJECTIVES:The optimal method of identifying people with asthma from electronic health records in primary care is not known. The aim of this study is to determine the positive predictive value (PPV) of different algorithms using clinical codes and prescription data to identify people with asthma in the United Kingdom Clinical Practice Research Datalink (CPRD). METHODS:684 participants registered with a general practitioner (GP) practice contributing to CPRD between 1 December 2013 and 30 November 2015 were selected according to one of eight predefined potential asthma identification algorithms. A questionnaire was sent to the GPs to confirm asthma status and provide additional information to support an asthma diagnosis. Two study physicians independently reviewed and adjudicated the questionnaires and additional information to form a gold standard for asthma diagnosis. The PPV was calculated for each algorithm. RESULTS:684 questionnaires were sent, of which 494 (72%) were returned and 475 (69%) were complete and analysed. All five algorithms including a specific Read code indicating asthma or non-specific Read code accompanied by additional conditions performed well. The PPV for asthma diagnosis using only a specific asthma code was 86.4% (95% CI 77.4% to 95.4%). Extra information on asthma medication prescription (PPV 83.3%), evidence of reversibility testing (PPV 86.0%) or a combination of all three selection criteria (PPV 86.4%) did not result in a higher PPV. The algorithm using non-specific asthma codes, information on reversibility testing and respiratory medication use scored highest (PPV 90.7%, 95%?CI (82.8% to 98.7%), but had a much lower identifiable population. Algorithms based on asthma symptom codes had low PPVs (43.1% to 57.8%)%). CONCLUSIONS:People with asthma can be accurately identified from UK primary care records using specific Read codes. The inclusion of spirometry or asthma medications in the algorithm did not clearly improve accuracy. ETHICS AND DISSEMINATION:The protocol for this research was approved by the Independent Scientific Advisory Committee (ISAC) for MHRA Database Research (protocol number15_257) and the approved protocol was made available to the journal and reviewers during peer review. Generic ethical approval for observational research using the CPRD with approval from ISAC has been granted by a Health Research Authority Research Ethics Committee (East Midlands-Derby, REC reference number 05/MRE04/87).The results will be submitted for publication and will be disseminated through research conferences and peer-reviewed journals.

SUBMITTER: Nissen F

PROVIDER: S-EPMC5724126 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

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Validation of asthma recording in the Clinical Practice Research Datalink (CPRD).

Nissen Francis F Morales Daniel R DR Mullerova Hana H Smeeth Liam L Douglas Ian J IJ Quint Jennifer K JK

BMJ open 20170811 8

<h4>Objectives</h4>The optimal method of identifying people with asthma from electronic health records in primary care is not known. The aim of this study is to determine the positive predictive value (PPV) of different algorithms using clinical codes and prescription data to identify people with asthma in the United Kingdom Clinical Practice Research Datalink (CPRD).<h4>Methods</h4>684 participants registered with a general practitioner (GP) practice contributing to CPRD between 1 December 2013 ...[more]

PMID: 28801439

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Project description:IntroductionWarfarin has frequently been underused in older people for stroke prevention in atrial fibrillation (AF). Direct oral anticoagulants (DOACs) entered the UK market from 2008 and have been recommended as an alternative to warfarin. This study aimed to describe any changes in the prescribing of oral anticoagulants (OACs) to people aged ?75 years in UK general practice before and after the introduction of DOACs, to examine differences in patient characteristics which may influence prescribers' decisions regarding anticoagulation, to evaluate the time people stay on OACs and switching between OACs.Methods and analysisA retrospective cohort study design will be used. Patients with a diagnosis of AF will be identified from the Clinical Practice Research Datalink (CPRD). The study period will run from 1 January 2003 to 27 December 2017. Patients enter the cohort at the latest date of the start of the study period, first AF diagnosis, 75th birthday or a year from when they started to contribute research standard data. Follow-up continues until they leave the practice, death, the date the practice stops contributing research standard data or the end of the study period (27 December 2017). Exposure to OACs will be defined as ?1 prescription issued for an OAC of interest during the study period. Patients issued an OAC in the year preceding study entry will be defined as 'prevalent users'. Patients starting on an OAC during the study period will be defined as 'incident users'. Incidence and prevalence of OAC prescribing, patient demographics and characteristics will be described during three time periods: 2003-2007, 2008-2012 and 2013-2017. Persistence (defined as the time from initiation to discontinuation of medication) with and switching between different OACs will be described.Ethics and disseminationThe protocol for this study was approved by the CPRD Independent Scientific Advisory Committee. The results will be disseminated in a peer-reviewed journal and at conferences.Trial registration numberEUPAS29923.

Project description:BackgroundPrimary care databases represent a rich source of data for health care research; however, the quality of recording of secondary care events in these databases is uncertain. This study sought to investigate the completeness of recording of hospital admissions for bleeds in primary care records and explore the impact of incomplete recording on estimates of bleeding risk associated with antithrombotic treatment.MethodsThe study population consisted of adults with non-valvular atrial fibrillation who had at least one bleed recorded in either the Clinical Practice Research Datalink (CPRD) or Hospital Episode Statistics (HES) while receiving prescriptions for an oral anticoagulant. The proportion of bleeds recorded in HES that had a corresponding bleed recorded in the subsequent 12 weeks in CPRD was calculated, and factors associated with having a corresponding record were identified. Cox proportional hazards analyses investigating the hazard of subsequent bleeding associated with antithrombotic treatment were carried out using linked CPRD-HES data and using CPRD only data, and the results were compared.ResultsLess than 20% of the 14,361 bleeds recorded in the HES data had a corresponding bleed coded in the CPRD in the subsequent 12 weeks. This proportion varied by bleed characteristics, calendar time, day of week of admission (weekday vs weekend) and oral anticoagulant treatment at the time of the bleed. The hazard of subsequent bleeding associated with vitamin K antagonists (VKAs) and antiplatelet agents (APAs) relative to no antithrombotic treatment were similar using the linked primary and secondary care dataset (VKA HRadj 1.06 CI95 0.96-1.16; APA HRadj 1.08 CI95 0.96-1.21) and the unlinked primary care data (VKA HRadj 1.12 CI95 1.01-1.24; APA HRadj 1.06 CI95 0.95-1.20).ConclusionSecondary care bleeding events are not completely recorded in primary care records and under-recording may be differential with respect to a variety of factors, including antithrombotic treatment. While the impact of under-recording on estimates of the comparative safety of antithrombotic drugs was limited, the extent of the under-recording suggests its potential impact should be considered, and ideally evaluated in future studies utilizing standalone primary care data.

Project description:INTRODUCTION:Epilepsy is highly prevalent in tuberous sclerosis complex (TSC), a multi-system genetic disorder. The clinical and economic burden of this condition is expected to be substantial due to treatment challenges, debilitating co-morbidities and the relationship between TSC-related manifestations. This study estimated healthcare resource utilisation (HCRU) and costs for patients with TSC with epilepsy (TSC+E) in the UK. METHODS:Patients with TSC+E in the Clinical Practice Research Datalink (CPRD) linked to Hospital Episodes Statistics were identified from April 1997 to March 2012. Clinical data were extracted over the entire history, and costs were reported over the most recent 3-year period. HCRU was compared with a matched Comparator cohort, and the key cost drivers were identified by regression modelling. RESULTS:In total, 209 patients with TSC+E were identified, of which 40% recorded ?2?other primary organ system manifestations and 42% had learning disability. Treatment with ?2?concomitant antiepileptic drugs (AEDs) was prevalent (60%), potentially suggesting refractory epilepsy. Notwithstanding, many patients with TSC+E (12%) had no record of AED use in their entire history, which may indicate undertreatment for these patients.Brain surgery was recorded in 12% of patients. Routine electroencephalography and MRI were infrequently performed (30% of patients), yet general practitioner visits, hospitalisations and outpatient visits were more frequent in patients with TSC+E than the Comparator. This translated to threefold higher clinical costs (£14?335 vs £4448), which significantly increased with each additional primary manifestation (p<0.0001). CONCLUSIONS:Patients with TSC+E have increased HCRU compared with the general CPRD population, likely related to manifestations in several organ systems, substantial cognitive impairment and severe epilepsy, which is challenging to treat and may be intractable. Disease surveillance and testing appears to be inadequate with few treatments trialled.Multidisciplinary care in TSC clinics with specialist neurologist input may alleviate some of the morbidity of patients, but more innovative treatment and management options should be sought.

Dataset Information

Validation of asthma recording in the Clinical Practice Research Datalink (CPRD).

Publications

Validation of asthma recording in the Clinical Practice Research Datalink (CPRD).

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