Longitudinal Research in Pediatric Psychology: An Introduction to the Special Issue

includes articles submitted for a special issue on "Longi- tudinal Research in Pediatric Psychology." In the Call for Papers, we sought empirically oriented manuscripts that employed longitudinal designs and theoretical, methodological, or statistical papers relevant to longitu- dinal research. Examples of potential topics were pro- vided in the Call and included: (a) familial, peer, and/or other contextual predictors of subsequent change in health-compromising behaviors in typically developing children or change in health-related behaviors and pro- cesses in children with chronic illness, (b) the impact of chronic illness on normative development or the conse- quences of varying developmental trajectories for subse- quent health-related behaviors and processes, (c) studies that isolate different health trajectories as well as predic- tors of such differential outcomes, (d) tests of prospec- tive mediational or causal predictor models based on longitudinal data, and (e) prevention, health promotion, and intervention studies with multiple data collection points that identify intervening mechanisms of change in health outcome. In response to the Call for Papers, 15 manuscripts were submitted. This issue includes eight of these articles; the first focuses on statistical strategies that can be used with longitudinal data and the other seven papers are empirical studies. Longitudinal studies permit examination of changes in health-related behaviors and processes over time. Such designs can be retrospective or prospective, with the latter