Measures of continuity of care. A register-based correlation study.

In an empirical study using data from a health center in Sweden, correlation coefficients were computed among nine different measures of continuity of care, five of them visit-based and four individual-based. Generally, the correlations were high. This may be due, in part, to the similar behavior of the measures for people making few visits. The correlations were also quite high, however, when the sample was restricted to people with many visits. Several measures display a significant dependence on utilization level. The results suggest that, for general purposes, the measure COC should be preferred among the individual-based measures and fraction-of-care continuity among the visit-based measures. On grounds of flexibility and ease of interpretation, the authors recommend fraction-of-care measures.