Balancing Contamination and Referral Bias in a Randomized Clinical Trial: An Application of Pseudo-Cluster Randomization.

Balancing Contamination and Referral Bias in a Randomized Clinical Trial: An Application of Pseudo-Cluster Randomization. Am J Epidemiol. 2015 Dec 1; Authors: Pence BW, Gaynes BN, Thielman NM, Heine A, Mugavero MJ, Turner EL, Quinlivan EB Abstract In randomized trials of provider-focused clinical interventions, treatment allocation often cannot be blinded to participants, study staff, or providers. The choice of unit of randomization (patient, provider, or clinic) entails tradeoffs in cost, power, and bias. Provider- or clinic-level randomization can minimize contamination, but it incurs the equally problematic potential for referral bias; that is, because arm assignment of future participants generally cannot be concealed, differences between arms may arise in the types of patients enrolled. Pseudo-cluster randomization is a novel study design that balances these competing validity threats. Providers are randomly assigned to an imbalanced proportion of intervention-arm participants (e.g., 80% or 20%). Providers can be masked to the imbalance, avoiding referral bias. Contamination is reduced because only a minority of control-arm participants are treated by majority-intervention providers. Pseudo-cluster randomization was implemented in a randomized trial of a decision support intervention to manage depression among patients receiving human immunodeficiency virus care in the southern United States in 2010-2014. The design appears suc...
Source: Am J Epidemiol - Category: Epidemiology Authors: Tags: Am J Epidemiol Source Type: research