Shortening the questionnaire for identifying children with chronic conditions: what is the consequence?

To determine whether a reduced item set can identify children who have chronic conditions with a level of at least 90% accuracy compared with the complete Questionnaire for Identifying Children With Chronic Conditions (QuICCC).

The QuICCC was developed to operationalize a conceptually based, noncategorical definition of chronic conditions developed by Stein et al. It contains 39 item sequences administered to a parent that assess 3 types of consequences: functional limitations; reliance on compensatory mechanisms or assistance; and service use or need above usual for age. The QuICCC has been validated and widely adopted as a means of identifying children without using a diagnosis checklist, but there is considerable interest in shortening it.

Through secondary analyses of 3 data sets (Ns = 1265, 1388, and 4831), we identified a short list of items that identified >90% of children who were identified by the 39-item QuICCC. We administered these 16 items to 2 new samples of parents. In Study 1 we administered the 16 items in the shortened version first, followed by the other 23 items, and compared the results on the short and reordered long versions. In Study 2, the 39- and 16-item versions were each administered, one in person and the other by phone, in random order to the same respondent within a 2-week period. These data were analyzed to compare the short and longer versions at the 2 time points and within the single, longer 39-item format (simultaneous data).

In Study 1 (N = 630) only 4 children were missed by the 16-item version who were identified by the longer version (sensitivity 98.6%; specificity 100%; positive predictive value 100%; negative predictive value 98.8% kappa 0.987). In Study 2 (N = 552), no children were missed by the 16-item subset of the 39 items when looking at the simultaneous data. When the two forms were administered 2 weeks apart, the 16-item version had a sensitivity of 87%, specificity of 90%, positive predictive value of 93%, negative predictive value of 82%, and kappa of 0.78 compared with the longer QuICCC. These results correspond exactly to the data obtained in a 2-week test-retest study for the QuICCC itself. The new form (the QuICCC-R) takes <2 minutes to administer on average (range 1-4 minutes) compared with 7 to 8 minutes for the full QuICCC.

The results met our criteria for agreement, and we conclude that the QuICCC-R is a satisfactory alternative for screening populations. However, the full QuICCC has other applications beyond screening that may not apply to the QuICCC-R, the shorter version.