The Wall of Evidence for Continuity of Care: How Many More Bricks Do We Need?

Continuity of care is a core value of primary health care.^1-4 It is highly valued by patients and general practitioners (GPs).^5,6 According to the late Barbara Starfield, continuity should be both relational and informational to be effective.⁷ To date, numerous studies have demonstrated continuity of care to be associated with multiple benefits for patients, doctors, and health systems. These benefits include reduced mortality rates,^8-11 fewer hospital admissions,^8,12,13 fewer emergency department (ED) visits,^14,15 reduced health care costs,^16,17 increased physician productivity,¹⁸ better uptake of preventive care,^19,20 better medication adherence,^21-23 more appropriate prescribing,^24,25 improved quality of life,²⁶ a better patient clinician relationship,^27,28 improved patient satisfaction,^29-31 and physician satisfaction.³²

The last decade, these benefits have been consistently demonstrated across different patient populations, including patients with diabetes,^33,34 cardiovascular disease,³⁵ severe mental illness,^36-38 dementia,^39,40 older patients (ie, 80% or more aged ≥ 65 years),^41,42 and children.⁴³ The evidence base for continuity of care continues to grow, giving rise to multiple systematic reviews for various outcome measures.^{9,10,12,16,17,24,34,37} Also, study results have been reproduced and replicated—using different continuity measures in both comparable and different populations, leading to an increasingly robust wall of evidence.

Despite this wall of evidence, continuity of care in family practice has been in sharp decline over the past decades— both in the United Kingdom and the United States,^44-46 negatively affecting health outcomes for patients, doctors, and society. Previously, this decline was mainly explained qualitatively or narratively: eg, patients and doctors are increasingly mobile, solo practice is becoming rare, the number of patients with chronic diseases—and corresponding multiple professionals employed by different organizations—is rising, family physicians (FPs) tend to reorganize themselves in large-group practices, other health care workers such as the practice nurse have entered family practice, on-call services are increasingly organized on a large scale, and patients prefer to prioritize access over continuity.^1,2,47-50 Only recently, Kajari-Montag et al used a data set of primary care consultations corresponding to 10% of England’s population over 10 years and found that approximately 45% of the decline in continuity of care can be explained by the increasing fragmentation of the workforce, caused by FPs shifting to part-time work patterns and greater dependence on temporary staff, and a sustained increase in workload caused by greater patient volumes without a proportionate increase in physician hours.⁵¹

In this issue of Annals of Family Medicine, Terrence McDonald and colleagues provide—to quote Pink Floyd—“another brick in the wall” of evidence supporting continuity of care.⁵² They conducted a retrospective cross-sectional study of FPs and their patients in Alberta, Canada, from 2015-2018 to explore the impact of primary care clinic continuity, distinct from relational continuity with an individual FP, on patient health outcomes. Separating the relative continuity contributions of a practice and an individual provider is an approach I have not encountered before. The researchers found higher physician continuity to be associated with lower ED use across all levels of patient complexity and lower hospital utilization at a high level of patient complexity. Given the used continuity measure—ie, known provider continuity index (KPC), an outcome measure almost identical to the usual provider of care (UPC) measure,⁵³ the found inverse association between physician continuity and ED and hospital use was not unexpected.^8,12-15 Perhaps more importantly, however, McDonald et al also demonstrated the benefit of clinic continuity, showing the strongest association with reduced ED and hospital use for patients who always saw either their own FP or one of her/his partners. Such a “buddy system” has been previously suggested as a way to promote continuity,^54,55 but has never actually been investigated for its added value. Scientific evidence like this is crucial, because it provides a glimpse into possible solutions that are feasible and future proof. Similarly, physicians should become more aware of the demonstrated dose-dependent association between continuity and key outcomes like hospitalization and mortality.^8,56,57 Such dose-dependency also provides hope for feasible solutions, ie, continuity of care is not a binary problem that needs to be solved by a binary solution, but a societal challenge that asks for continuity awareness and multiple, partial solutions that all contribute to overall improvement of continuity of care. Examples of such solutions, in addition to a buddy system, may include personal lists, implementation of e-health (consultation by video call, e-mail or chat), structural education of FP trainees on the benefits of continuity and how to deliver it,^5,58 and, if possible, using a stepwise, structured approach to implement selected solutions.⁵⁵

At the beginning of the 1980s, my dad and granddad— both solo FPs in a small village—told me “although we cannot prove it, we are convinced that knowing your patient is crucial for health outcomes.” They were right, because—despite being a core value—the empirical evidence for continuity was still anecdotal at the time. Forty years later, the constantly growing wall of evidence for continuity cannot be ignored, leading to the question: how many more bricks before we— patients, physicians, health insurers, and policy makers—fully commit to promoting continuity in primary care?