Letters Section Editor: Jody W. Zylke, MD, Senior Editor.
Author Affiliations: Department of Pulmonary and Critical Care Medicine, Stanford University Medical Center, Stanford, California (email@example.com).
To the Editor: Dr Pletcher and colleagues1 studied the association between marijuana and pulmonary function over 20 years. Although all survey analyses can be limited by recall bias,2 the risk of bias in this study may be greater than usual. Cognitive deficits may exist in chronic marijuana users that are dose-dependent, with higher doses leading to poorer recall.3,4 Such decline in long-term memory may result in inaccurate recollection of smoking frequency, particularly during the 10-year intervals between interviews in the Coronary Artery Risk Development in Young Adults (CARDIA) study population.
Patel RB, Khazeni N. Long-term Marijuana Use and Pulmonary Function. JAMA. 2012;307(17):1796-1797. doi:10.1001/jama.2012.3570