Developing concise measures of childhood activity limitations.

OBJECTIVES: Although several national health surveys have implemented data collection efforts to identify and characterize disability among children, the large number of items these surveys have required to measure childhood disability prohibit their use in general population surveys. Using a conceptually based approach, we examine whether concise sets of survey items--feasible for use in general population surveys--can be used to measure functional limitations in activities among children.
METHODS: We analyze three nationally representative population surveys that contain detailed questions on childhood activity limitations. We first examine the full set of survey items and then eliminate survey items, one by one, exploring different combinations and examining the results of each successive elimination.
RESULTS: Across the three surveys, we consistently demonstrate that it is possible to reduce the number of survey items needed to measure childhood activity limitations and still produce comparable estimates. Concise sets of measures may contain as few as six items, making it possible to include in general population surveys. However, our concise sets of measures do not produce comparable estimates across surveys, which reflects differences in the types of questions and differences in the wording of questions found in the original survey instruments.
CONCLUSIONS: On the basis of our findings, we reemphasize the importance of the wording of survey questions, the importance of validating survey questions, and finally, we recommend a concise set of items that can be used to measure childhood activity limitations in general population surveys.