Retirement and elderly health in China: Based on propensity score matching

Background

The relationship between retirement and health is important to the formulation of retirement related policies but is a controversial topic, perhaps because selection bias has not been well-addressed in previous studies through traditional analysis methods. Using data from the China Health and Retirement Longitudinal Study (CHARLS), this study explored the potential impact of retirement on the health of elderly Chinese individuals, adjusting for selection bias.

Methods

We balanced the baseline differences between retirement groups and working groups based on nearest neighbor matching and genetic matching with a generalized boosted model (GBM), and regression analysis was used to evaluate the impact of retirement on the health of elderly individuals.

Results

No significant difference was found in any of the covariates between the two groups after matching. Genetic matching performed better than nearest neighbor matching in balancing the covariates. Compared to the working group, the retirement group had a 0.78 (95% CI: 0.65-0.94, P = 0.026) times higher probability of self-reported physical pain, a 0.76 (95% CI: 0.62-0.93, P = 0.023) times higher probability of depression, and a 0.57-point (95% CI: 0.37-0.78, P < 0.001) improvement in cognitive status score. Among male, the retirement group had a 0.89-point (95% CI: 0.45-1.33, P < 0.001) improvement in cognitive status score for low education, a 0.65 (95% CI: 0.46-0.92, P = 0.042) times higher probability of self-reported physical pain for middle education. For female with low education, the cognitive status of the retirement group was significantly higher by 0.99 points (95% CI: 0.42-1.55, P = 0.004), the probability of depression was 0.56 (95% CI: 0.36-0.87, P = 0.031) times higher in the retirement group than in the working group. There was no difference for the middle and high education.

Conclusion

Retirement can exert a beneficial effect on the health of elderly individuals. Therefore, the government and relevant departments should consider this potential effect when instituting policies that delay retirement.

The relative effectiveness of eribulin for advanced breast cancer treatment: a study of the southeast Netherlands advanced breast cancer registry

Background: Eribulin provided significant overall survival (OS) benefit in heavily pretreated advanced breast cancer patients in the EMBRACE trial. We investigated the use of eribulin in daily clinical practice, the relative effectiveness of eribulin versus non-eribulin chemotherapy, and the safety of eribulin in real-world patients included in the SOutheast Netherlands Advanced BREast cancer (SONABRE) registry.Material and methods: Patients treated with eribulin and eligible patients for eribulin who received a different chemotherapy (i.e., non-eribulin group) in ten hospitals in 2013-2017 were included. A multivariate matching algorithm was applied to correct for differences in baseline characteristics between the groups, including the number of previous treatment lines. Progression-free survival (PFS) and OS of eribulin were compared with the matched non-eribulin group through Kaplan-Meier curves and multivariate Cox proportional hazard models. The occurrence of dose delay and reduction was described.Results: Forty-five patients received eribulin according to its registration criteria and 74 patients were eligible for eribulin but received non-eribulin chemotherapy. Matching increased the similarity in baseline characteristics between the eribulin and non-eribulin groups. Median PFS was 3.5 months (95% confidence interval (CI): 2.7-5.5) in the eribulin group and 3.2 months (95% CI: 2.0-4.8) in the matched non-eribulin group (adjusted hazard ratio (HR): 0.83, 95% CI: 0.49-1.38). Median OS was 5.9 months (95% CI: 4.6-11.0) and 5.2 months (95% CI: 4.6-9.5) in the eribulin and non-eribulin groups, respectively (adjusted HR: 0.66, 95% CI: 0.38-1.13). Dose delay or reduction occurred in 14 patients (31%) receiving eribulin.Conclusions: No difference in PFS and OS was observed between eribulin and non-eribulin treated patients. Eribulin had a manageable toxicity profile.

How robust are reference pricing studies on outpatient medical procedures? Three different preprocessing techniques applied to difference-in differences

The evaluation of policies that are not randomly assigned on outcomes generated by nonlinear data generating processes often requires modeling assumptions for which there is little theoretical guidance. This paper revisits previously published difference-in-differences results of an important example, the introduction of reference pricing to common outpatient procedures, to assess the robustness of the estimated impacts by using different matching, and reweighting techniques to preprocess the data. These techniques improve covariate balance and reduce model dependence. Specifically, we examine the robustness of the effect of reference pricing on patient site-of-care choice, total expenditures, and complication rates. We apply three preprocessing methods: propensity score reweighting, exact matching, and genetic matching. Propensity score reweighting is a technique for achieving covariate balance but does not balance higher-order moments and may lead to bias and inefficiency in estimating treatment effects in the context of nonlinear data generating processes. In contrast, exact matching and genetic matching are designed to balance higher-order moments. We find that although the use of the preprocessing techniques is a valuable robustness check showing that some results are sensitive to the method used, the three approaches generally yield results that do not statistically differ from the published results.