Voucher-based reinforcement for alcohol abstinence using the ethyl-glucuronide alcohol biomarker.

The team worked with the adults who wanted to stop drinking. Each person gave urine and breath samples three times a week.

When both tests showed no alcohol, the person got a voucher worth $5 to $25. The voucher value grew with each clean test. If a test showed drinking, the next voucher dropped back to $5.

The researchers used an ABAB design. They turned the vouchers on for two weeks, off for two weeks, on again, then off again. This let them see if the vouchers truly caused the change.

Abstinence jumped from a large share to a large share when vouchers were active. The jump happened every time the vouchers came back on.

When vouchers stopped, drinking quickly returned to baseline. The ethyl-glucuronide (EtG) urine test caught alcohol use within two days, faster than breath alone.

Pirnia et al. (2016) ran a similar prize system with cocaine users and also saw more clean urines. Together, the two studies show the same token-economy rule works across different drugs.

Potter et al. (2013) took the voucher idea but paid homeless adults for job-training attendance instead of abstinence. Their results extend this work: contingency management can boost engagement even when the target is sobriety-supporting skills, not the drug use itself.

Jones et al. (1977) used tokens to keep teens on dialysis from gaining too much fluid weight. Like Duerden et al. (2012), when the tokens stopped, the healthy behavior dropped. This pattern shows the rule is general—reinforcement maintains behavior, removal loses it.

You can now test alcohol use within 48 hours using a simple urine dipstick. Pair that test with escalating vouchers and you double the chance adults stay dry. If you run an intensive outpatient program, add EtG testing to your CM protocol and watch for the same reversal pattern—when incentives end, plan booster vouchers or transfer to natural reinforcers like job pay to keep gains.