Background Improvements in primary care quality are often proposed as a solution to rises in emergency department (ED) attendances. However, there is little agreement on what constitutes an avoidable attendance, and the relationship between primary care quality and ED demand remains poorly understood.

Objective To estimate the size of the associations between primary care quality and volumes of ED attendances classified as avoidable.

Methods Retrospective observational study of all attendances at EDs in England during 2015/2016, applying three definitions of avoidable attendance. We linked practice-level counts of attendances to seven measures of primary care access, patient experience and clinical quality for 7521 practices. We used count data regressions to associate attendance counts with levels of quality. We then calculated proportions of attendances associated with levels of primary care quality below the national average.

Results Attendance volumes were negatively related to three of the seven quality measures. Incidence rate ratios (IRRs) for all attendances associated with 10 percentage-point differences in quality were 0.987 for clinical quality and 0.987 for easy telephone access and 0.978 for ability to get an appointment. These associations were relatively stronger for narrower definitions of avoidable attendances (for the narrowest definition, IRRs=0.966, 0.976 and 0.934, respectively) but represented fewer attendances in absolute terms. 341 000 (2.4%) attendances were associated with levels of primary care quality below the national average in 2015/2016.

Conclusion ED attendances are sensitive to primary care quality, but magnitudes of these associations are small. Attendances are much less responsive to differences in primary care quality than indicated by estimates of the prevalence of avoidable attendances. This may explain the failure of initiatives to reduce attendances through primary care improvements.