Summary
In this article the authors have defined, created, and applied a measure of the complexity of general practice consultations which can be applied to routine electronic medical records. This measure was constructed using characteristics of patients and problems selected by a consensus process involving experienced GPs, demonstrating face validity. The measure has been validated by showing that each of the characteristics in the final selection, and the overall complexity measure, are associated with consultation duration in two independent samples of consultations.
Strengths and limitations
This study has several limitations. The concept of complexity in consultations is nebulous, and though widely recognised by clinicians, it is hard to define.13,16 The present definition of complexity encompasses intellectual, emotional, and workload demands, but other definitions of complexity would lead to different measurement tools. The choice of complexity factors was based on the experience of the research team and the literature, with additional factors suggested by the GPs in the Delphi panel, but other factors could have been considered. Some factors may add complexity to consultations but are not coded within electronic medical records. In this study some factors were dropped, such as medically unexplained symptoms, which almost certainly generate complexity within consultations but are rarely coded, so inclusion would add little to the measure when used for analysis at a population level. Two variables (patients with dementia or patients who are housebound) had a statistically significant negative association with consultation duration. In post-hoc analysis it was found that these characteristics were associated with more consulting time over a whole year, resulting from a higher number of consultations that are shorter than average.
The development of the complexity measure was conducted in England, and factors that cause consultation complexity may differ in other countries, for example insurance status in the US.13,14 The complexity measure developed here was based on a sample of consultations taken 6 years ago. This was deliberate to create a baseline against which to assess changes in complexity over time in a subsequent article. However, in this study the authors have revalidated the findings in a more recent dataset (2017/2018) and this analysis largely confirmed the present findings.
The authors recognise that mean duration of consultations is not a gold standard for complexity, since the length of a consultation is only partly related to complexity and not all complex consultations are lengthy. However, it was the best and simplest (while imperfect) proxy available within routine medical records. The purpose of the cross-sectional analysis was not to derive a model to predict consultation duration, but to provide evidence for the construct validity of the present complexity measure by showing a positive association with a variable (duration) that the authors hypothesised would be related to it. The analysis fulfilled the present aims by confirming: that each of the included complexity factors was independently associated with longer consultations; that a measure defined as the presence of ≥1 of these factors was discriminating, with complex consultations being on average 9% longer than non-complex consultations; and that these findings were robust when repeated in a different data sample. Though the complexity measure is useful as a binary ‘complex/non-complex’ variable, the authors do not propose combining the factors to create a cumulative score (see statistical note in Supplementary Box 1).
The present measure is reliable in that it is based on objective analysis of medical records and defined code sets for complexity factors, unlike measures that require subjective judgements.4,7,13,17 Basing the measure on the views of practising GPs and assessing the relationship with consultation duration provides evidence of face and construct validity respectively.
Further validation exercises could explore the relationship between the present complexity measure and other variables, such as practitioners’ self-assessment of the complexity of a sample of consultations. Future research should also explore the relationship between complexity and risk prediction models for healthcare utilisation. The authors anticipate some, but not complete, overlap.14 It is likely that different tools will be best at predicting different outcomes and measures should be used in combination to understand population healthcare needs.18
Comparison with existing literature
The presented research builds on previous research. Two studies4,7 and an online survey2 have asked primary care clinicians to record the complexity of their consultations subjectively, for example using a five-point scale from very simple to very complex, while another study quantified the number and range of problems discussed within consultations.19 Three studies have asked GPs about features that make patients complex, and the present authors build on this by considering aspects of consultations as well as patients.12,14,15,20 A few previous authors have devised case-mix measures applicable to primary care, but these have either not taken account of clinicians’ perceptions of the complexity of different factors21–24 or not been designed for analysis of routine medical records.13,17
There is some overlap between measures of complexity and case-mix measures such as Adjusted Clinical Groups,25 Rx-Risk26 and the Charlson score,27 which have been designed to predict health outcomes, resource utilisation, or mortality. These case-mix measures are based on combinations of diagnostic information, medication data and/or demographic factors but do not account for social, behavioural, or other psychological factors,11 which often create the greatest demands on GPs within consultations12,15,16,20 and are captured by the present complexity measure
Implications for research and practice
This article describes a valid and reliable measure of the complexity of GPs’ consultations. In future research the authors plan to explore the complexity of consultations in different settings and populations, and how complexity has changed over time. This may be relevant to the development of resource allocation formulae. The current UK formula for allocating payments to primary care takes account of the number of expected consultations based on characteristics of the practice population, but not the complexity of those consultations.28 Practices that have a high proportion of complex consultations may need a different mix of staff than practices with few complex consultations. There is growing interest in creating population health management systems by linking health and social care datasets to understand current and future health and care needs.29 Use of a complexity measure may support this aim, providing greater nuance and understanding by taking account of the different workforce, workload, and resource implications of consultations with different levels of complexity.