Resolving the milk addiction paradox.

The milk addiction paradox refers to an empirical finding in which consumption of non-addictive commodities such as milk appears to be consistent with the theory of rational addiction. This paradoxical result seems more likely when consumption is persistent and with aggregate data. Using both simulated and real data, we show that the milk addiction paradox disappears when estimating the data using an AR(1) linear specification that describes the saddle-path solution of the rational addiction model, instead of the canonical AR(2) model. The AR(1) specification is able to correctly discriminate between rational addiction and simple persistence in the data, to test for the main features of rational addiction, and to produce unbiased estimates of the short and long-run elasticity of demand. These results hold both with individual and aggregated data, and they imply that the AR(1) model is a better empirical alternative for testing rational addiction than the canonical AR(2) model.

Serum uric acid levels and the risk of recurrent venous thromboembolism.

Essentials Increase in serum uric acid (SUA) levels has been widely associated with higher risk of cardiovascular disease. We investigated the link between SUA levels and the risk of venous thromboembolism (VTE) recurrence. Patients with SUA levels ≥ 4.38 mg/dL showed a three-fold increase in the risk of VTE recurrence. Elevated SUA levels are associated with increased risk of recurrent VTE independently from traditional risk factors. ABSTRACT: Background The link between serum uric acid (SUA) and the risk of cardiovascular disease is well established. However, the impact of SUA levels on the risk of venous thromboembolism (VTE) recurrence is unknown. Objectives To investigate the association between SUA and the risk of VTE recurrence. Patients and Methods We performed a monocenter, prospective study on 280 patients with a previous episode of VTE that completed the oral anticoagulant period. SUA levels at enrollment were correlated with the risk of VTE recurrence (mean follow-up 71.1 ± 29.2 months). Results Patients were stratified according to SUA tertiles distribution at baseline (tertiles cut-off: I ≤ 4.37 mg/dL, II 4.38--5.54 mg/dL, III ≥ 5.55 mg/dL). Fifty episodes of VTE recurrence occurred during the follow-up and Kaplan-Meier survival analysis showed that subjects in the lower tertile of SUA distribution had significantly lower risk of future VTE recurrence (P = .003). No differences were seen among patients belonging to the second and the third tertile of SUA distribution. A multivariate Cox regression analysis showed that higher tertiles of SUA distribution had about three-fold increase in the risk of VTE recurrence as compared to subjects with SUA ≤ 4.37, independently from potential confounders (hazard ratio [HR] 3.04, 95% confidence interval [CI] 1.15--8.05 P = .025). Moreover, we observed that the adjusted hazard of VTE recurrence increased by 30% for each additional unit of SUA (mg/dL; HR 1.30, 95% CI 1.01--1.22, P = .040). Conclusion Elevated SUA levels are associated with increased risk of future VTE recurrence independently from traditional risk factors.