Journal of clinical epidemiology
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To raise awareness among clinicians and epidemiologists that single-patient (n-of-1) trials are potentially useful for informing personalized treatment decisions for patients with chronic conditions. ⋯ Single-patient trials may be poised to emerge as an important part of the methodological armamentarium for comparative effectiveness research and patient-centered outcomes research. By permitting direct estimation of individual treatment effects, they can facilitate finely graded individualized care, enhance therapeutic precision, improve patient outcomes, and reduce costs.
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As psychopathology and social functioning can worsen with repeated psychotic episodes in schizophrenia, relapse prevention is critical. Because high nonadherence rates limit the efficacy of pharmacotherapy, the use of long-acting injectable (LAI) antipsychotics is considered an important treatment option. To date, many studies comparing LAIs and oral antipsychotics have been conducted; however, the results are mixed, and careful interpretation of the data is required. ⋯ Divergent results from studies using different methodologies create a dilemma for comparative effectiveness research, and LAI studies may serve as an example of a situation in which a conventional RCT is not the gold standard. Traditional RCTs generally increase adherence compared with clinical practice and, therefore, might not be well suited to detect differences between LAIs and oral medications, because any increase in adherence affects patients on oral medications more than those on LAIs and thus leads to an underestimation of any potential difference in effectiveness. A possible solution would be the implementation of a true effectiveness trial in which post-randomization involvement would be kept to a minimum to better reflect routine practice.
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Examining covariate balance is the prescribed method for determining the degree to which propensity score methods should be successful at reducing bias. This study assessed the performance of various balance measures, including a proposed balance measure based on the prognostic score (similar to a disease risk score), to determine which balance measures best correlate with bias in the treatment effect estimate. ⋯ Researchers should consider using prognostic score-based balance measures for assessing the performance of propensity score methods for reducing bias in nonexperimental studies.
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Comparative Study
Impact of immortal person-time and time scale in comparative effectiveness research for medical devices: a case for implantable cardioverter-defibrillators.
To assess the extent of immortal time bias in estimating the clinical effectiveness of implantable cardioverter-defibrillators (ICDs) and the impact of methods of handling immortal time bias. ⋯ Immortal time bias was detected in the ICD clinical effectiveness study, which might have led to substantial bias overestimating the treatment effect if handled by exclusion. When an appropriate landmark was selected, that method yielded similar hazard ratios to those obtained by the Mantel-Byar method, supporting the validity of the landmark method.
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The need to identify how best to structure health insurance and to deliver health care services is a central priority for comparative effectiveness research. Studies designed to evaluate these issues are frequently conducted in large insurance systems. We sought to describe the challenges faced when conducting trials in this context. ⋯ Studies in insurance settings are a powerful and necessary design for evaluating comparative effectiveness interventions. There are numerous strategies to address the potential logistical and methodological challenges that this research environment uniquely creates.