Disentangling dimension issues of the Patient Assessment of Chronic Illness Care (PACIC) instrument by using published validation models and data from Swiss diabetic patients

Abstract

Introduction: The Chronic Care Model (CCM) identifies six key elements susceptible to improve care of patients with chronic diseases. The Patient Assessment of Chronic Illness Care (PACIC) questionnaire allows these patients to assess their care and see whether it is congruent with the CCM. However, validation analyses have delivered heterogeneous results across studies. Aims: To understand the dimensions of the PACIC instrument better. More specifically, to revisit all published validation models, using one single dataset and statistical tools adapted to the ordinal structure of the data. Methods: The analytical sample included 406 randomly selected non-institutionalized diabetic patients >18y of age. A French version of the 20-items PACIC questionnaire was used. We conducted descriptive analyses to check data quality of the 20 items, and used three types of confirmatory factor analysis (CFA) to test the five most often described and published dimensions. Results: Nearly 77% of respondents completed all items (range of missing values 5.7%-12.3%). Their responses showed strong floor and ceiling effects (7% to 67% and 4% to 46% of patients ticked the lowest and highest answering category, respectively). Even though loadings of the five tested models were relatively high, the only model showing acceptable to good fits was the 11items single dimension model. Variables known to be associated with PACIC usual five dimensions were related to this unique dimension. Conclusions: Results suggest that the PACIC questionnaire presents a unique dimension. Such a score may be used instead of the five previously described dimensions.