A Vigilante in Statistical Badlands

This study, for instance, attributes a patient’s waitlist/transplant outcome to the very last dialysis facility the patient was associated with.  In epidemiology speak, this means the causal inference authors are trying to draw between for-profit status and good transplant outcomes is subject to time-varying confounding. As an example, if one is seeking an association between testosterone levels and risk of a heart attack, using the last testosterone level available would be a poor way of doing this study because testosterone levels are known to vary over time. The same applies to dialysis facilities. Patients change dialysis facilities, and facilities may change their profit status if ownership changes. Eric did his own sensitivity analysis (personal communication), and this time changed the profit status indicator to the dialysis facility on record after 3 months of dialysis as opposed to the last dialysis facility – the difference in outcomes seen is even further attenuated.  The choice of the last dialysis facility prior to waitlisting is particularly interesting given that most waitlist activity happens in the first 2 years of getting on dialysis.   Clinical reality would suggest that what would be of most interest to physicians and patients alike would be the discovery of dialysis facilities that are not aggressive in referring patients for transplant early after patients initiate dialysis.  But beyond the somewhat esoteric discussions of how much expo...
Source: The Health Care Blog - Category: Consumer Health News Authors: Tags: Medical Practice Physicians Eric Weinhandl JAMA medical research public health Public Policy public policy research Source Type: blogs