RT Journal Article SR Electronic T1 Measuring the complexity of general practice consultations: development and validation of a complexity measure JF British Journal of General Practice JO Br J Gen Pract FD British Journal of General Practice SP BJGP.2020.0486 DO 10.3399/BJGP.2020.0486 A1 Chris Salisbury A1 Sarah Lay-Flurrie A1 Clare Bankhead A1 Alice Fuller A1 Mairead Murphy A1 Barbara Caddick A1 Jose Ordóñez-Mena A1 Tim Holt A1 Brian D Nicholson A1 Rafael Perera A1 FD Richard Hobbs YR 2020 UL http://bjgp.org/content/early/2020/12/21/BJGP.2020.0486.abstract AB Background: The complexity of general practice consultations may be increasing and vary in different settings. Testing these hypotheses requires a measure of complexity. Aim: To develop a valid measure of general practice consultation complexity applicable to routine medical records. Design: Delphi study to select potential indicators of complexity followed by cross-sectional study to develop and validate a complexity measure. Setting: English general practices. Method: An online Delphi study over two rounds involved 32 general practitioners to identify potential indicators of consultation complexity. The cross-sectional study used an age-sex stratified random sample of 173,130 patients and 725,616 general practice face-to-face consultations from 2013/14 in the Clinical Practice Research Datalink. We explored independent relationships between each indicator and consultation duration using mixed effects regression models, and revalidated findings using data from 2017/18. We assessed the proportion of complex consultations in different age-sex groups. Results: After two rounds, the Delphi panel endorsed 34 of 45 possible complexity indicators. In the cross-sectional study, after excluding factors because of low prevalence or confounding, 17 indicators were retained. Defining complexity as the presence of any of these factors, 308,370 consultations (42.5%) were complex. Mean duration of complex consultations was 10.49 minutes, compared to 9.64 minutes for non-complex consultations. The proportion of complex consultations was similar in men and women but increased with age. Conclusion: Our consultation complexity measure has face and construct validity. It may be useful for research, management and policy, informing decisions about the range of resources needed in different practices.