ABSTRACT
OBJECTIVE: To estimate, from a Filipino societal perspective, the cost-effectiveness of preventing atopic dermatitis (AD) via early nutritional intervention with 100% whey-based partially hydrolyzed formula (PHF-W) versus standard cow's milk formula (SF) in healthy, urban infants with atopic heredity who are not exclusively breast-fed. METHODS: A Markov model was used to simulate over 6 years the incidence of AD, days with AD symptoms, quality-adjusted life-years (QALYs), and AD-related direct and indirect (i.e., parents'/caregivers' productivity loss) costs incurred by hypothetical cohorts of healthy, at-risk infants fed with either PHF-W or SF as AD prevention for ≤ 17 weeks. Efficacy estimates of PHF-W versus SF in preventing AD were literature-based. The resources used to manage AD (by severity, age, and treatment modality) were estimated using clinical pathways derived from clinical expert opinion. Local costs were applied to resource use. Results were presented as point estimates and as 95 percent credible intervals (CIs, i.e., range of values around the point estimate that include 95% of model simulations) generated via multivariate probabilistic sensitivity analysis using Monte-Carlo simulation techniques. All costs are reported in Philippines pesos (â±, where â±1000 = US $22.24). All reported outcomes were discounted at a rate of 3.5% per year. RESULTS: Based on the 6-year simulation, compared with SF, PHF-W was predicted to result in a 14-percentage point reduction (i.e., 39% vs. 25%) (95% CI 0.09-0.19) in the incidence of AD and a gain of 0.03 (i.e., 5.46 vs. 5.43) (95% CI 0.01-0.07) QALYs/patient. PHF-W's higher feeding formula cost (+â±1,304/patient) (95% CI -â±3,090 to â±5,779) were offset by reductions in AD-related costs (-â±11,959/patient; i.e., â±27,228 vs. â±15,269) (95% CI -â±14,685 to -â±7,284), including, in particular, the costs of pharmacotherapy, formula used as treatment, and visits to physicians. As a result, PHF-W became a net cost-saving strategy within 38 weeks. Overall, PHF-W resulted in net savings of -â±10,654 (-US $237) (CI -â±4,240 [-US $94] to -â±14,544 [-US $323]) (i.e., â±27,228 [US $606] vs. â±16,574 [US $369]). Sensitivity analysis confirmed the robustness of results; the most influential variable was the first-year risk reduction in AD. CONCLUSIONS: Based on the present modeling exercise, compared with SF, PHF-W appears to substantially reduce the risk of AD and its associated direct and indirect medical costs in healthy, at-risk urban Filipino infants over a 6-year period.
ABSTRACT
Researchers can rely either on retrospectively reported or on prospectively measured health changes to identify and quantify recent changes in respondents' health status. The two methods typically do not provide the same answers. We compare the validity of prospective versus retrospective measures of health changes by investigating their predictive power for subsequent mortality. Data from a cohort study conducted in the Netherlands are used to compare the ability of changes in self-assessed health (SAH) - either reported retrospectively or measured prospectively in three waves (1991, 1993 and 1995) - to predict survival until 2004. We examine the relationship between health changes and mortality with a proportional hazard models controlling for individual unobserved heterogeneity, with and without control for pre-existing chronic conditions and the onset of new chronic diseases. For a high proportion of reports (39.8%), prospectively measured health changes in SAH do not concur with retrospectively reported health changes. Our results show that both measures of health changes are predictive of mortality in the model controlling for levels of SAH and socioeconomic characteristics only. Controlling for SAH, prior presence of chronic conditions, the onset of new conditions and unobserved characteristics, we find that prospectively reported health changes still predict longevity, whereas retrospective changes do not. These results suggest that the collection of longitudinal information on health changes has advantages over the - easier and cheaper - option of retrospective collection of the same information.
