ClinicalCodes.org

An online clinical codes repository to improve validity and reproducibility of medical database research

Research article:

Can analyses of electronic patient records be independently and externally validated? The effect of statins on the mortality of patients with Ischaemic heart disease: a cohort study with nested case-control analysis

Reference:

David Reeves, David Springate, Darren M Ashcroft, Ronan Ryan, Tim Doran, Richard Morris, Ivan Olier, Evangelos Kontopantelis(2014) Can analyses of electronic patient records be independently and externally validated? The effect of statins on the mortality of patients with Ischaemic heart disease: a cohort study with nested case-control analysis. BMJ Open, doi: doi:10.1136/bmjopen-2014-004952

Link to fulltext article
Abstract
Objective To conduct a fully independent and external validation of a research study based on one electronic health records database, using a different electronic database sampling the same population. Design Using the Clinical Practice Research Datalink (CPRD), we replicated a published investigation into the effects of statins in patients with ischaemic heart disease (IHD) by a different research team using QResearch. We replicated the original methods and analysed all cause mortality using: (i) a cohort analysis and (ii) a case-control analysis nested within the full cohort. Setting Electronic health record databases containing longitudinal patient consultation data from large numbers of general practices distributed throughout the UK. Participants CPRD data for 34925 patients with IHD from 224 general practices, compared against previously published results from QResearch for 13,029 patients from 89 general practices. The study period was January 1996 to December 2003. Results We successfully replicated the methods of the original study very closely. In cohort analysis risk of death was lower by 55% for patients on statins, compared to 53% for QResearch (adjusted HR 0.45, 95% CI 0.40 to 0.50; versus 0.47, 95% CI 0.41 to 0.53). In case-control analyses patients on statins had a 31% lower odds of death, compared to 39% for QResearch (adjusted OR 0.69, 95% CI 0.63 to 0.75; versus OR 0.61, 95% CI 0.52 to 0.72). Results were also close for individual statins. Conclusion Database differences in population characteristics and in data definitions, recording, quality and completeness had minimal impact on key statistical outputs. The results uphold the validity of research using CPRD and QResearch, by providing independent evidence that both datasets produce very similar estimates of treatment effect, leading to the same clinical and policy decisions. Together with other, non-independent, replication studies there is a nascent body of evidence for wider validity.
Author for correspondence
David Reeves
Email for correspondence
david.reeves@manchester.ac.uk

Code list: Body_mass_index

65 codes in list

Code Coding system Description Entity type List name
22A..00 Read O/E - weight observation Body_mass_index
22A1.00 Read O/E - weight > 20% below ideal observation Body_mass_index
22A2.00 Read O/E -weight 10-20% below ideal observation Body_mass_index
22A3.00 Read O/E - weight within 10% ideal observation Body_mass_index
22A4.00 Read O/E - weight 10-20% over ideal observation Body_mass_index
22A4.11 Read O/E - overweight observation Body_mass_index
22A5.00 Read O/E - weight > 20% over ideal observation Body_mass_index
22A5.11 Read O/E - obese observation Body_mass_index
22A6.00 Read O/E - Underweight observation Body_mass_index
22K..00 Read Body Mass Index observation Body_mass_index
22K1.00 Read Body Mass Index normal K/M2 observation Body_mass_index
22K2.00 Read Body Mass Index high K/M2 observation Body_mass_index
22K3.00 Read Body Mass Index low K/M2 observation Body_mass_index
22K4.00 Read Body mass index index 25-29 - overweight observation Body_mass_index
22K5.00 Read Body mass index 30+ - obesity observation Body_mass_index
22K6.00 Read Body mass index less than 20 observation Body_mass_index
22K7.00 Read Body mass index 40+ - severely obese observation Body_mass_index
22K8.00 Read Body mass index 20-24 - normal observation Body_mass_index
22Z..00 Read Height and Weight observation Body_mass_index
636..00 Read Birthweight of baby observation Body_mass_index
636..11 Read Birthweight observation Body_mass_index
636..12 Read Weight - baby observation Body_mass_index
636Z.00 Read Birthweight of baby NOS observation Body_mass_index
647..00 Read Child weight centiles observation Body_mass_index
6471.00 Read Child weight < 3rd centile observation Body_mass_index
6472.00 Read Child weight=3rd-9th centile observation Body_mass_index
6473.00 Read Child weight=10th-24th centile observation Body_mass_index
6474.00 Read Child weight=25th-49th centile observation Body_mass_index
6475.00 Read Child weight=50th-74th centile observation Body_mass_index
6476.00 Read Child weight=75th-89th centile observation Body_mass_index
6477.00 Read Child weight=90th-96th centile observation Body_mass_index
6478.00 Read Child weight > 97th centile observation Body_mass_index
6479.00 Read Child weight < 0.4th centile observation Body_mass_index
647A.00 Read Child weight = 0.4th centile observation Body_mass_index
647B.00 Read Child weight 0.5th - 1.9th centile observation Body_mass_index
647C.00 Read Child weight = 2nd centile observation Body_mass_index
647D.00 Read Child weight 3rd - 8th centile observation Body_mass_index
647E.00 Read Child weight 9th centile observation Body_mass_index
647F.00 Read Child weight 10th - 24th centile observation Body_mass_index
647G.00 Read Child weight = 25th centile observation Body_mass_index
647H.00 Read Child weight 26th - 49th centile observation Body_mass_index
647I.00 Read Child weight = 50th centile observation Body_mass_index
647J.00 Read Child weight 51st - 74th centile observation Body_mass_index
647K.00 Read Child weight = 75th centile observation Body_mass_index
647L.00 Read Child weight 76th - 90th centile observation Body_mass_index
647M.00 Read Child weight = 91st centile observation Body_mass_index
647N.00 Read Child weight 92nd - 97th centile observation Body_mass_index
647O.00 Read Child weight = 98th centile observation Body_mass_index
647P.00 Read Child weight 98.1st - 99.6th centile observation Body_mass_index
647Q.00 Read Child weight > 99.6th centile observation Body_mass_index
647Z.00 Read Child weight centiles NOS observation Body_mass_index
Q111.00 Read Premature - weight 1000g-2499g or gestation of 28-37weeks observation Body_mass_index
Q114.00 Read Low birthweight observation Body_mass_index
Q114000 Read Birth weight 1000-2499 g observation Body_mass_index
Q115.00 Read Extremely low birth weight infant observation Body_mass_index
Q115000 Read Birth weight 999 g or less observation Body_mass_index
Q120.00 Read Very large baby - weight greater than 4500gm observation Body_mass_index
L3333NA OXMIS WEIGHT ABNORMAL RANGE RECORDED observation Body_mass_index
L3333NN OXMIS WEIGHT NORMAL RANGE RECORDED observation Body_mass_index
T3324PW OXMIS PERCENTILE WEIGHT observation Body_mass_index
T3324WC OXMIS WEIGHT CHECK observation Body_mass_index
T3326BA OXMIS PERCENTILE WEIGHT OUTSIDE 5% RANGE observation Body_mass_index
T3326BC OXMIS PERCENTILE WEIGHT WITHIN 10% RANGE observation Body_mass_index
Y060 AY OXMIS SCREENING WEIGHT observation Body_mass_index
Y060 CY OXMIS SCREENING WEIGHT ABNORMAL observation Body_mass_index

0 comments have been posted.

Please log in to leave a comment.

Quick links:

Code list links:

Only the original uploading author or an administrator can add, edit or delete this article and its associated codes.

University of Manchester IPH ClinicalCodes is a project at the University of Manchester Institute of Population Health

Funded by NIHR School for Primary Care The ClinicalCodes project is funded by the National Institute for Health Research (NIHR) School for Primary Care Research (SPCR)

© 2013-2014 University of Manchester all rights reserved