Validation of suicide and self-harm records in the Clinical Practice Research Datalink
Article first published online: 20 JUN 2013
© 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society
British Journal of Clinical Pharmacology
Volume 76, Issue 1, pages 145–157, July 2013
How to Cite
Thomas, K. H., Davies, N., Metcalfe, C., Windmeijer, F., Martin, R. M. and Gunnell, D. (2013), Validation of suicide and self-harm records in the Clinical Practice Research Datalink. British Journal of Clinical Pharmacology, 76: 145–157. doi: 10.1111/bcp.12059
- Issue published online: 20 JUN 2013
- Article first published online: 20 JUN 2013
- Accepted manuscript online: 6 DEC 2012 06:34AM EST
- Manuscript Accepted: 30 NOV 2012
- Manuscript Received: 10 SEP 2012
- Medicines and Healthcare products Regulatory Agency. Grant Number: SDS 33437
- Clinical Practice Research Datalink;
- General Practice Research Database;
- nonfatal self-harm;
The UK Clinical Practice Research Datalink (CPRD) is increasingly being used to investigate suicide-related adverse drug reactions. No studies have comprehensively validated the recording of suicide and nonfatal self-harm in the CPRD. We validated general practitioners' recording of these outcomes using linked Office for National Statistics (ONS) mortality and Hospital Episode Statistics (HES) admission data.
We identified cases of suicide and self-harm recorded using appropriate Read codes in the CPRD between 1998 and 2010 in patients aged ≥15 years. Suicides were defined as patients with Read codes for suicide recorded within 95 days of their death. International Classification of Diseases codes were used to identify suicides/hospital admissions for self-harm in the linked ONS and HES data sets. We compared CPRD-derived cases/incidence of suicide and self-harm with those identified from linked ONS mortality and HES data, national suicide incidence rates and published self-harm incidence data.
Only 26.1% (n = 590) of the ‘true’ (ONS-confirmed) suicides were identified using Read codes. Furthermore, only 55.5% of Read code-identified suicides were confirmed as suicide by the ONS data. Of the HES-identified cases of self-harm, 68.4% were identified in the CPRD using Read codes. The CPRD self-harm rates based on Read codes had similar age and sex distributions to rates observed in self-harm hospital registers, although rates were underestimated in all age groups.
The CPRD recording of suicide using Read codes is unreliable, with significant inaccuracy (over- and under-reporting). Future CPRD suicide studies should use linked ONS mortality data. The under-reporting of self-harm appears to be less marked.