Does pooling saliva for cotinine testing save money without losing information?

Abstract

Although testing for cotinine in saliva offers an attractive means to verify survey responses about recent use of tobacco, its relatively high cost prevents its use in many studies of substance use. Pooling two or more samples can dramatically reduce the cost when prevalence rates are low, but many researchers fear that failures in detecting users will outweigh the monetary benefit. Results from pools of two saliva specimens collected from seventh-grade students provide the first empirical evidence that pooling saves money without compromising the test's accuracy to detect recent tobacco use. Pooling successfully identified all specimens near or above the 10-ng/ml threshold for evidence of active tobacco exposure. We conclude that analysts can realize substantial savings by pooling saliva samples from young populations without losing valuable information.