My colleagues and I agree with van der Steen that confounding by indication is an important concern in nonrandomized studies assessing treatment outcomes. Propensity score adjustment is one method used to address this concern. However, in our study the use of a propensity score to account for the likelihood of antimicrobial treatment yielded results similar to the analysis presented in the published article. While we acknowledge the lack of information on physicians’ prognosis in our study, the CASCADE (Choices, Attitudes, and Strategies for Care of Advanced Dementia at the End-of-Life)1 study participants are a homogeneous population of patients with end-stage dementia, and we have controlled for any differences in functional impairment with a valid instrument. In addition, our analysis adjusted for markers of palliative treatment including hospice enrollment and do-not-hospitalize orders. Our results show that subjects receiving antimicrobial treatment had an average increase in life expectancy of several months’ duration, rather than a few days, compared with those who did not receive treatment.
Givens J. Prolonged Life and Increased Symptoms vs Prolonged Dying and Increased Comfort After Antibiotic Treatment in Patients With Dementia and Pneumonia—Reply. Arch Intern Med. 2011;171(1):94. doi:10.1001/archinternmed.2010.488