Do-it-yourself biospecimens: the benefits of home collection.

Epidemiologic studies often rely on biospecimen analysis to reveal variables that influence or indicate a population's health. Collection of biospecimens places some burden on participants, which may in turn affect participation rates and compliance. In this month's issue, researchers led by John C. Rockett of the U.S. Environmental Protection Agency National Health and Environmental Effects Research Laboratory weigh for the first time the utility and potential value of home-based biospecimen collection in a large longitudinal study [EHP 112:94-104]. Their findings indicate that home-based collection of biospecimens might relieve some of the burden, thereby increasing participation and compliance.

Rockett and colleagues provide this review as background for the design of the proposed National Children's Study. This multiagency study is being planned to follow 100,000 children from before birth through their late teens. It will require the collection and analysis of biospecimens from the children as well as their parents. Among other end points, analyses will reveal participants' environmental exposures to a wide array of natural and synthetic chemicals. Some exposures may occur during embryonic or early fetal development, and advice on study design has been solicited from experts in fertility and early pregnancy. They present their findings as a mini-monograph in this month's issue.

In their contribution to the mini-monograph, Rockett and colleagues say that home-based biospecimen collection is usually more convenient and private for epidemiologic study participants. The researchers hypothesize that these attributes might bolster participation rates and propose testing whether this theory holds true for various types of biospecimens and across multiple socioeconomic groups.

Biospecimens that have a history of successful home collection include urine, blood, and semen. Collection is not complicated, although blood samples almost always must be drawn by trained staff. Urine, blood, and semen samples are typically transported and analyzed as fluids, but some analyses can be accomplished with blood or urine that is collected and dried on filter paper.

Less commonly used biospecimens include saliva, breast milk, hair and hair follicles, nails, and buccal (inner cheek) cells. Such samples may be simpler, less invasive, or less costly to collect compared to the more common biospecimens, but they may also yield more limited data. Rockett and colleagues describe some of the data these less commonly used samples can yield, and point out that more consistent methods for collection and analysis are needed to standardize samples taken at different sites and to better allow for cross-study comparisons.

The researchers caution that quality control can be complicated in home collection. Study participants must be able to understand and follow directions for sample collection and storage. Further, it's necessary to specify the conditions under which samples will be transported to clinics or laboratories, and to know how stable samples remain between collection and delivery. Laboratory receipt, storage, and analysis compose another area for consideration in study planning.

With more complete information about home-based biospecimen collection, researchers could develop better procedures and integrate a wider range of biospecimens into studies. This would enhance the quality of epidemiologic studies.