{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T05:47:36Z","timestamp":1789192056829,"version":"build-2803163510"},"reference-count":55,"publisher":"BMJ","issue":"2","license":[{"start":{"date-parts":[[2024,2,14]],"date-time":"2024-02-14T00:00:00Z","timestamp":1707868800000},"content-version":"unspecified","delay-in-days":13,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["220283\/Z\/20\/Z"],"award-info":[{"award-number":["220283\/Z\/20\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2024,1,16]]},"published-print":{"date-parts":[[2024,2]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To explore whether UK primary care databases arising from two different software systems can be feasibly combined, by comparing rates of Huntington\u2019s disease (HD, which is rare) and 14 common cancers in the two databases, as well as characteristics of people with these conditions.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Descriptive study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Primary care electronic health records from Clinical Practice Research Datalink (CPRD) GOLD and CPRD Aurum databases, with linked hospital admission and death registration data.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>4986 patients with HD and 1\u2009294\u2009819 with an incident cancer between 1990 and 2019.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary and secondary outcome measures<\/jats:title>\n                    <jats:p>Incidence and prevalence of HD by calendar period, age group and region, and annual age-standardised incidence of 14 common cancers in each database, and in a subset of \u2018overlapping\u2019 practices which contributed to both databases. Characteristics of patients with HD or incident cancer: medical history, recent prescribing, healthcare contacts and database follow-up.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Incidence and prevalence of HD were slightly higher in CPRD GOLD than CPRD Aurum, but with similar trends over time. Cancer incidence in the two databases differed between 1990 and 2000, but converged and was very similar thereafter. Participants in each database were most similar in terms of medical history (median standardised difference, MSD 0.03 (IQR 0.01\u20130.03)), recent prescribing (MSD 0.06 (0.03\u20130.10)) and demographics and general health variables (MSD 0.05 (0.01\u20130.09)). Larger differences were seen for healthcare contacts (MSD 0.27 (0.10\u20130.41)), and database follow-up (MSD 0.39 (0.19\u20130.56)).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Differences in cancer incidence trends between 1990 and 2000 may relate to use of a practice-level data quality filter (the \u2018up-to-standard\u2019 date) in CPRD GOLD only. As well as the impact of data curation methods, differences in underlying data models can make it more challenging to define exactly equivalent clinical concepts in each database. Researchers should be aware of these potential sources of variability when planning combined database studies and interpreting results.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2022-070258","type":"journal-article","created":{"date-parts":[[2024,2,14]],"date-time":"2024-02-14T20:05:17Z","timestamp":1707941117000},"page":"e070258","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":5,"title":["Pooling of primary care electronic health record (EHR) data on Huntington\u2019s disease (HD) and cancer: establishing comparability of two large UK databases"],"prefix":"10.1136","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3699-5391","authenticated-orcid":false,"given":"Daniel","family":"Dedman","sequence":"first","affiliation":[{"name":"Clinical Practice Research Datalink, Medicines and Healthcare Products Regulatory Agency, London, UK"},{"name":"Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rachael","family":"Williams","sequence":"additional","affiliation":[{"name":"Clinical Practice Research Datalink, Medicines and Healthcare Products Regulatory Agency, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krishnan","family":"Bhaskaran","sequence":"additional","affiliation":[{"name":"Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ian J","family":"Douglas","sequence":"additional","affiliation":[{"name":"Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2024,2,14]]},"reference":[{"key":"2025121221313042000_14.2.e070258.1","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kwt010"},{"key":"2025121221313042000_14.2.e070258.2","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1002\/pds.3828","article-title":"Data management and data analysis techniques in pharmacoepidemiological studies using a pre-planned multi-database approach: a systematic literature review","volume":"24","author":"Bazelier","year":"2015","journal-title":"Pharmacoepidemiol Drug Saf"},{"key":"2025121221313042000_14.2.e070258.3","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2020-037405","article-title":"Approaches for combining primary care electronic health record data from multiple sources: a systematic review of observational studies","volume":"10","author":"Dedman","year":"2020","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.4","unstructured":"CPRD . CPRD GOLD release notes. 2022 Available: https:\/\/www.cprd.com\/sites\/default\/files\/2022-02 CPRD GOLD Release Notes.pdf"},{"key":"2025121221313042000_14.2.e070258.5","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyv098"},{"key":"2025121221313042000_14.2.e070258.6","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2016-012785","article-title":"Evolution of primary care databases in UK: a scientometric analysis of research output","volume":"6","author":"Vezyridis","year":"2016","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.7","unstructured":"Clinical Practice Research Datalink . CPRD bibliography. 2022. Available: https:\/\/www.cprd.com\/bibliography"},{"key":"2025121221313042000_14.2.e070258.8","doi-asserted-by":"publisher","DOI":"10.14236\/jhi.v24i3.942"},{"key":"2025121221313042000_14.2.e070258.9","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2125.2009.03537.x"},{"key":"2025121221313042000_14.2.e070258.10","doi-asserted-by":"publisher","DOI":"10.3399\/bjgp10X483562"},{"key":"2025121221313042000_14.2.e070258.11","doi-asserted-by":"publisher","DOI":"10.1592\/phco.23.5.686.32205"},{"key":"2025121221313042000_14.2.e070258.12","unstructured":"CPRD . CPRD Aurum release notes. 2022 Available: https:\/\/www.cprd.com\/sites\/default\/files\/2022-02"},{"key":"2025121221313042000_14.2.e070258.13","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyz034"},{"key":"2025121221313042000_14.2.e070258.14","doi-asserted-by":"crossref","first-page":"1134","DOI":"10.1002\/pds.4996","article-title":"Quality and completeness of diagnoses recorded in the new CPRD Aurum database: evaluation of pulmonary embolism","volume":"29","author":"Jick","year":"2020","journal-title":"Pharmacoepidemiol Drug Saf"},{"key":"2025121221313042000_14.2.e070258.15","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2020-038767","article-title":"Comparison of antibiotic prescribing records in two UK primary care electronic health record systems: cohort study using CPRD GOLD and CPRD Aurum databases","volume":"10","author":"Gulliford","year":"2020","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.16","doi-asserted-by":"crossref","first-page":"179","DOI":"10.2147\/CLEP.S337323","article-title":"Trends in the Annual consultation incidence and prevalence of low back pain and osteoarthritis in England from 2000 to 2019: comparative estimates from two clinical practice databases","volume":"14","author":"Yu","year":"2022","journal-title":"Clin Epidemiol"},{"key":"2025121221313042000_14.2.e070258.17","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1002\/pds.5188","article-title":"Feasibility of using clinical practice research datalink data to identify patients with chronic obstructive pulmonary disease to enrol into real-world trials","volume":"30","author":"Requena","year":"2021","journal-title":"Pharmacoepidemiol Drug Saf"},{"key":"2025121221313042000_14.2.e070258.18","doi-asserted-by":"publisher","DOI":"10.1007\/s10654-018-0442-4"},{"key":"2025121221313042000_14.2.e070258.19","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyx015"},{"key":"2025121221313042000_14.2.e070258.20","unstructured":"Office for National Statistics . User guide to mortality statistics. Available: https:\/\/www.ons.gov.uk\/peoplepopulationandcommunity\/birthsdeathsandmarriages\/deaths\/methodologies\/userguidetomortalitystatisticsjuly2017 [Accessed 25 Sep 2022]."},{"key":"2025121221313042000_14.2.e070258.21","unstructured":"Cancer registration statistics: England 2018 final release [National Statistics]. 2020. Available: https:\/\/www.gov.uk\/government\/statistics\/cancer-registration-statistics-england-2018-final-release"},{"key":"2025121221313042000_14.2.e070258.22","unstructured":"NHS Business Services Authority . Dictionary of medicines and devices (Dm+D). 2019. Available: https:\/\/www.nhsbsa.nhs.uk\/pharmacies-gp-practices-and-appliance-contractors\/dictionary-medicines-and-devices-dmd [Accessed 07 Jul 2022]."},{"key":"2025121221313042000_14.2.e070258.23","unstructured":"NHSDigital . NHSBSA Dm+D supplementary. 2022. Available: https:\/\/isd.digital.nhs.uk\/trud\/users\/authenticated\/filters\/0\/categories\/6\/items\/25\/releases [Accessed 14 Feb 2022]."},{"key":"2025121221313042000_14.2.e070258.24","unstructured":"NHSBSA . BNF SNOMED mapping. Available: https:\/\/www.nhsbsa.nhs.uk\/prescription-data\/understanding-our-data\/bnf-snomed-mapping [Accessed 10 Aug 2022]."},{"key":"2025121221313042000_14.2.e070258.25","doi-asserted-by":"publisher","DOI":"10.1080\/00273171.2011.568786"},{"key":"2025121221313042000_14.2.e070258.26","doi-asserted-by":"publisher","DOI":"10.1016\/S0895-4356(00)00321-8"},{"key":"2025121221313042000_14.2.e070258.27","doi-asserted-by":"publisher","DOI":"10.1093\/eurheartj\/ehi890"},{"key":"2025121221313042000_14.2.e070258.28","unstructured":"Read codes [NHS Digital]. n.d. Available: https:\/\/digital.nhs.uk\/services\/terminology-and-classifications\/read-codes"},{"key":"2025121221313042000_14.2.e070258.29","unstructured":"SCIMP guide to read codes | Primary care Informatics. 2014. Available: https:\/\/www.scimp.scot.nhs.uk\/better-information\/clinical-coding\/scimp-guide-to-read-codes [Accessed 07 Apr 2022]."},{"key":"2025121221313042000_14.2.e070258.30","unstructured":"SNOMED CT 5-step briefing [SNOMED International]. 2022. Available: https:\/\/www.snomed.org\/snomed-ct\/five-step-briefing"},{"key":"2025121221313042000_14.2.e070258.31","unstructured":"NHS Digital . Guidance for primary care: transitioning from read to SNOMED CT; 2016. 23. Available: https:\/\/www.networks.nhs.uk\/nhs-networks\/snomed-ct\/snomed-ct-learning\/guidance-for-primary-care-transitioning-from-read-to-snomed-ct [Accessed 20 Nov 2018]."},{"key":"2025121221313042000_14.2.e070258.32","unstructured":"LSHTM data compass. Available: https:\/\/datacompass.lshtm.ac.uk\/ [Accessed 28 Apr 2022]."},{"key":"2025121221313042000_14.2.e070258.33","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2020-037719","article-title":"What are the implications of using individual and combined sources of routinely collected data to identify and characterise incident site-specific cancers? A concordance and validation study using linked English electronic health records data","volume":"10","author":"Strongman","year":"2020","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.34","unstructured":"NHS Digital . NHS data migration: read version 2 to SNOMED CT mapping. 2020. Available: https:\/\/isd.digital.nhs.uk\/trud\/users\/authenticated\/filters\/0\/categories\/9\/items\/9\/releases [Accessed 23 Mar 2020]."},{"key":"2025121221313042000_14.2.e070258.35","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0212291","article-title":"Term sets: a transparent and reproducible representation of clinical code sets","volume":"14","author":"Williams","year":"2019","journal-title":"PLoS One"},{"key":"2025121221313042000_14.2.e070258.36","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijsu.2014.07.013"},{"key":"2025121221313042000_14.2.e070258.37","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2015-009070","article-title":"Incidence of adult Huntington\u2019s disease in the UK: a UK-based primary care study and a systematic review","volume":"6","author":"Wexler","year":"2016","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.38","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp-2012-304636"},{"key":"2025121221313042000_14.2.e070258.39","doi-asserted-by":"crossref","first-page":"2249","DOI":"10.1111\/ene.15385","article-title":"Natural history and burden of Huntington\u2019s disease in the UK: a population-based cohort study","volume":"29","author":"Furby","year":"2022","journal-title":"Eur J Neurol"},{"key":"2025121221313042000_14.2.e070258.40","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2017-020738","article-title":"Spatial distribution of clinical computer systems in primary care in England in 2016 and implications for primary care electronic medical record databases: a cross-sectional population study","volume":"8","author":"Kontopantelis","year":"2018","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.41","doi-asserted-by":"publisher","DOI":"10.1136\/amiajnl-2012-001081"},{"key":"2025121221313042000_14.2.e070258.42","first-page":"103","article-title":"Electronic patient record data as proxy of GPs\u2019 thoughts","volume":"141","author":"De Clercq","year":"2008","journal-title":"Stud Health Technol Inform"},{"key":"2025121221313042000_14.2.e070258.43","doi-asserted-by":"crossref","DOI":"10.1186\/1471-2296-4-14","article-title":"Implications of the problem orientated medical record (POMR) for research using electronic GP databases: a comparison of the Doctors Independent Network Database (DIN) and the General Practice Research Database (GPRD)","volume":"4","author":"Carey","year":"2003","journal-title":"BMC Fam Pract"},{"key":"2025121221313042000_14.2.e070258.44","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2016-012669","article-title":"Do GPs know their patients with cancer? Assessing the quality of cancer registration in Dutch primary care: a cross-sectional validation study","volume":"6","author":"Sollie","year":"2016","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.45","doi-asserted-by":"publisher","DOI":"10.1002\/pds.1688"},{"key":"2025121221313042000_14.2.e070258.46","doi-asserted-by":"publisher","DOI":"10.1002\/pds.3368"},{"key":"2025121221313042000_14.2.e070258.47","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/keab714"},{"key":"2025121221313042000_14.2.e070258.48","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0261983","article-title":"Prevalence and incidence of neuromuscular conditions in the UK between 2000 and 2019: a retrospective study using primary care data","volume":"16","author":"Carey","year":"2021","journal-title":"PLoS One"},{"key":"2025121221313042000_14.2.e070258.49","doi-asserted-by":"crossref","first-page":"423","DOI":"10.2147\/CLEP.S242065","article-title":"Evaluating the effectiveness of an additional risk minimization measure to reduce the risk of prescribing Mirabegron to patients with severe uncontrolled hypertension in four European countries","volume":"12","author":"Heintjes","year":"2020","journal-title":"Clin Epidemiol"},{"key":"2025121221313042000_14.2.e070258.50","doi-asserted-by":"crossref","DOI":"10.1136\/bmj.h5441","article-title":"Development and validation of risk prediction equations to estimate future risk of blindness and lower limb amputation in patients with diabetes: cohort study","volume":"351","author":"Hippisley-Cox","year":"2015","journal-title":"BMJ"},{"key":"2025121221313042000_14.2.e070258.51","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2015-008503","article-title":"Development and validation of risk prediction equations to estimate future risk of heart failure in patients with diabetes: a prospective cohort study","volume":"5","author":"Hippisley-Cox","year":"2015","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.52","doi-asserted-by":"publisher","DOI":"10.1038\/bjc.2013.383"},{"key":"2025121221313042000_14.2.e070258.53","doi-asserted-by":"crossref","DOI":"10.1136\/bmj.f114","article-title":"Exposure to bisphosphonates and risk of gastrointestinal cancers: series of nested case-control studies with QResearch and CPRD data","volume":"346","author":"Vinogradova","year":"2013","journal-title":"BMJ"},{"key":"2025121221313042000_14.2.e070258.54","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2014-005809","article-title":"The performance of seven QPrediction risk scores in an independent external sample of patients from general practice: a validation study","volume":"4","author":"Hippisley-Cox","year":"2014","journal-title":"BMJ Open"},{"key":"2025121221313042000_14.2.e070258.55","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2017-020827","article-title":"Cancer recording in patients with and without type 2 diabetes in the clinical practice research datalink primary care data and linked hospital admission data: a cohort study","volume":"8","author":"Williams","year":"2018","journal-title":"BMJ Open"}],"updated-by":[{"DOI":"10.1136\/bmjopen-2022-070258corr1","type":"correction","label":"Correction","source":"publisher","updated":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T00:00:00Z","timestamp":1750032000000}}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2022-070258","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T05:31:44Z","timestamp":1765603904000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2022-070258"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,2]]},"references-count":55,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2024,2,14]]},"published-print":{"date-parts":[[2024,2]]}},"alternative-id":["10.1136\/bmjopen-2022-070258"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2022-070258","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,2]]}}}