One of the few areas of studying research I ever enjoyed (which has meant wonders for my career as a research director) was the use of “unobtrusive measures,” the indirect way of measuring a concept, such as determining interest in exhibits at art museums by looking at wear of floor tiles or rugs around them. There’s a great “unobtrusive measure” being used in several cities, studying sewage for byproducts of drug use, as described in this Scientific American online article:
"Here's a new tool for taking snapshots of communities over space and in time and getting a less biased view of drug use," Field says. Current methods, she notes, rely on either self-reporting in surveys or actual overdoses. "Certainly compared to the statistics approach, which is waiting for people to die," she adds, "this is more real-time."
The technique has been tried in at least 10 U.S. cities, ranging from towns with populations hovering around 17,000 people to medium-size cities of 600,000, according to Fields, though she declined to specify the municipalities by name. One trend: use of methadone and methamphetamine (a prescription opiate withdrawal aid and speed) remained constant over 24 days in these cities, but cocaine consumption routinely spiked on the weekends. "You can see this upswing in the recreational use of cocaine as evidenced by increases in some cases starting as early as Thursday," of each week studied, Field says.
The technique might help communities determine where to apply law enforcement or track the success of targeted drug-use prevention efforts, the researchers say—for example, helping to get a handle on methamphetamine-related deaths in Oregon, which have tripled over the past decade. But the strategy also raises privacy concerns, Field says. She notes it would be extremely difficult to track individual drug use with this method, both because it is hard to reliably estimate from a community-wide measure how many individuals are actually using the drug and sampling would have to take place almost all the way back in the individual toilet to trace it to a particular household. "It's not getting back to the individual," she emphasizes.
The next step, Fields says, will be to trace the unique by-products of extremely common drugs, such as caffeine and nicotine, to enable even more precise readings of local use. "We will be exploring are there ways to use human urinary biomarkers to try and assess the population?" she says. "Can you follow worker populations? Students moving in and out? And then answer questions about trends in drug use."