No abstract

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.

A complex individual patient simulation model (UKPDS Outcome Model version 1.3) was used with quality adjusted life years (QALY) and cost of complications as model outputs. To reduce 1st-order uncertainty, 1000 patients were simulated for each input combination selected. ANN simulation meta-models using a sample of 200 individual runs were developed and cross-validated to approximate the original simulation as these do not require any specific input-output functional relationship and can handle any number of input parameters. Performance was compared with a Gaussian Process (GP) meta-model, and a valid and better predictive meta-model was then used for PSA. RESULTS: From ANN meta-models, the mean absolute percentage error (defined as positive difference between the predicted and true output divided by the range in true output) was 3.8 % for costs and 1.4% for QALYs compared with 5.1% and 2.1% in GP meta-models. The distribution of errors was approximately symmetrical around zero meaning that mean costs and QALYs for an intervention are unlikely to be affected by the small inaccuracies associated with ANN approximations. CONCLUSIONS: ANN produces better predictive capability than GP meta-models in estimating costs and QALYs from the UKPDS outcome model. A PSA carried out using the ANN meta-model demonstrated the potential for ANN in analysing complex health economic models.OBJECTIVES: Different methods of meta-analysis on model parameters can lead to different outcomes of cost-effectiveness (CE) modeling. As the "true" CE is unknown, it is unclear which method performs best. We compared different methods of meta-analysis with regards to the underlying "true" CE outcome. METHODS: In a simulation study we constructed two patient populations and their treatments ("truth"): a chronic disease with events and a progressive lethal disease. We drew trials from these populations, comparing two treatments, varying the number of trials, trial sizes and between-study heterogeneity in scenarios. From each trial utilities, transition and event probabilities, risk-differences and log-risk-ratios were estimated. These parameters were synthesized using frequentist fixed-effects (FFE) and random-effects (FRE), Bayesian fixed-effects (BFE) and random-effects (BRE) models. A CE model was filled and probabilistic sensitivity analysis was performed. We repeated this trial sampling, leading to 1000 sets of health economic outcomes for each scenario. We compared methods of meta-analysis on bias and coverage, the percentage of draws that the "true" outcome lies in the confidence interval. RESULTS: Even in the most heterogeneous scenario, biases were limited to approximately 5%, and similar for all methods, but small biases in individual treatment arms occasionally led to biases up to 30% in the difference between arms. FFE models consistently have lower coverage than BFE. With homogeneous trials, all methods have coverage above 80% for all outcomes. BRE has coverage higher than 99% for all outcomes, regardless of heterogeneity. With heter...

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. May 2015 Terms of use: Documents in AbstractBiased longevity expectations will lead to suboptimal decisions regarding saving, retirement, annuitization and health, with consequences for wellbeing in old age. Systematic differences in the accuracy of longevity expectations may partly explain heterogeneity in economic behaviour by education and cognitive functioning. Analysis of eight waves of the US Health and Retirement Study reveals that individuals with lower levels of education and cognitive functioning report survival probabilities that are less accurate in predicting their in-sample mortality. There is little evidence that the gradients in the veracity of expectations are due to the less educated and cognitively able responding less to changes in objective mortality risks. However, high school dropouts and the least cognitively able report survival probabilities that are less stable and display greater unexplained variability. These disadvantaged groups appear to be less confident in their longevity beliefs, which is justified given that their expectations are less accurate. JEL Classification: D83, D84, I12, J14Keywords: Expectations, Mortality, Health, Cognition, Education Acknowledgements: We thank Rob Alessie, Susann Rohwedder, Paul Lau, Martin Salm and Sílvia Sousa, as well as seminar and conference participants at Lancaster, Manchester, Netspar (Paris), SSPH+ (Grindelwald), ASHE (Los Angeles) and the University of Southern California for helpful comments.

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte.