Beyond Causality: Additional Benefits of Randomized Controlled Trials for Improving Health Care Delivery

Can propensity score matching replace randomized controlled trials?

Randomized controlled trials (RCTs) have long been recognized as the gold standard for establishing causal relationships in clinical research. Despite that, various limitations of RCTs prevent its widespread implementation, ranging from the ethicality of withholding potentially-lifesaving treatment from a group to relatively poor external validity due to stringent inclusion criteria, amongst others. However, with the introduction of propensity score matching (PSM) as a retrospective statistical tool, new frontiers in establishing causation in clinical research were opened up. PSM predicts treatment effects using observational data from existing sources such as registries or electronic health records, to create a matched sample of participants who received or did not receive the intervention based on their propensity scores, which takes into account characteristics such as age, gender and comorbidities. Given its retrospective nature and its use of observational data from existing sources, PSM circumvents the aforementioned ethical issues faced by RCTs. Majority of RCTs exclude elderly, pregnant women and young children; thus, evidence of therapy efficacy is rarely proven by robust clinical research for this population. On the other hand, by matching study patient characteristics to that of the population of interest, including the elderly, pregnant women and young children, PSM allows for generalization of results to the wider population and hence greatly increases the external validity. Instead of replacing RCTs with PSM, the synergistic integration of PSM into RCTs stands to provide better research outcomes with both methods complementing each other. For example, in an RCT investigating the impact of mannitol on outcomes among participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial, the baseline characteristics of comorbidities and current medications between treatment and control arms were significantly different despite the randomization protocol. Therefore, PSM was incorporated in its analysis to create samples from the treatment and control arms that were matched in terms of these baseline characteristics, thus providing a fairer comparison for the impact of mannitol. This literature review reports the applications, advantages, and considerations of using PSM with RCTs, illustrating its utility in refining randomization, improving external validity, and accounting for non-compliance to protocol. Future research should consider integrating the use of PSM in RCTs to better generalize outcomes to target populations for clinical practice and thereby benefit a wider range of patients, while maintaining the robustness of randomization offered by RCTs.

One-Third of Systematic Reviews in Rehabilitation Applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) System to Evaluate Certainty of Evidence: A Meta-Research Study

OBJECTIVE

To determine how many systematic reviews (SRs) of the literature in rehabilitation assess the certainty of evidence (CoE) and how many apply the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to do this.

DATA SOURCES

For this meta-research study, we searched PubMed and Cochrane Database of Systematic Reviews databases for SRs on rehabilitation published in 2020.

STUDY SELECTION AND DATA EXTRACTION

Two reviewers independently selected the SRs and extracted the data. Reporting characteristics and appropriate use of the GRADE system were assessed.

DATA SYNTHESIS

The search retrieved 827 records: 29% (239/827) SRs evaluated CoE, 68% (163/239) of which applied the GRADE system. GRADE was used by SRs of randomized controlled trials (RCTs, 88%; 144/163), non-randomized intervention studies (NRIS, 2%; 3/163), and both RCT and NRIS (10%; 16/163). In the latter case, a separate GRADE assessment according to the study design was not provided in 75% (12/16). The reasons for GRADE judgment were reported in 82% (134/163) of SRs.

CONCLUSIONS

One-third of SRs in rehabilitation assessed CoE with the GRADE system. GRADE assessment was presented transparently by most SRs. Journal editors and funders should encourage the uptake of the GRADE system when considering SRs in rehabilitation for publication. The authors should pre-define GRADE assessment in a registered and/or published protocol.

Improving Access to High-Value, High-Cost Medicines: The Use of Subscription Models to Treat Hepatitis C Using Direct-Acting Antivirals in the United States

State payers may face financial incentives to restrict use of high-cost medications. Yet, restrictions on access to high-value medications may have deleterious effects on population health. Direct-acting antivirals (DAAs), available since 2013, can cure chronic infection with hepatitis C virus (HCV). With prices upward of $90,000 for a treatment course, states have struggled to ensure access to DAAs for Medicaid beneficiaries and the incarcerated, populations with a disproportionate share of HCV. Advance purchase commitments (APCs), wherein a payer commits to purchase a certain quantity of medications at lower prices, offer payers incentives to increase access to high-value medications while also offering companies guaranteed revenue. This article discusses the use of subscription models, a type of APC, to support increased access to high-value DAAs for treating HCV. First, the authors provide background information about HCV, its treatment, and state financing of prescription medications. They then review the implementation of HCV subscription models in two states, Louisiana and Washington, and the early evidence of their impact. The article discusses challenges to evaluating state-sponsored subscription models, and it concludes by discussing implications of subscription models that target DAAs and other high-value, high-cost medicines.

Health Economics Research in Cancer Screening: Research Opportunities, Challenges, and Future Directions

Cancer screening has long been considered a worthy public health investment. Health economics offers the theoretical foundation and research methodology to understand the demand- and supply-side factors associated with screening and evaluate screening-related policies and interventions. This article provides an overview of health economic theories and methods related to cancer screening and discusses opportunities for future research. We review 2 academic disciplines most relevant to health economics research in cancer screening: applied microeconomics and decision science. We consider 3 emerging topics: cancer screening policies in national as well as local contexts, "choosing wisely" screening practices, and targeted screening efforts for vulnerable subpopulations. We also discuss the strengths and weaknesses of available data sources and opportunities for methodological research and training. Recommendations to strengthen research infrastructure include developing novel data linkage strategies, increasing access to electronic health records, establishing curriculum and training programs, promoting multidisciplinary collaborations, and enhancing research funding opportunities.