In Reply: Dr Kassabian raises the important point that a stronger study design would have included a third group to control for the nonspecific effects of the added attention the intervention participants received. For example, it is not known whether regular telephone calls from a lay peer counselor might have had the same effect. Without an attention-control condition, we can only speculate about the mechanisms whereby the intervention led to the observed improvements in mood and quality of life. This issue deserves greater attention in future studies.
Bakitas M, Lyons KD, Hegel MT. Study Design and Palliative Care Intervention—Reply. JAMA. 2009;302(23):2551. doi:10.1001/jama.2009.1829