Public Health and Changes in Illicit Drug Prices

In this issue of the Journal, Caulkins shows that in the United States between 1981 and 1996, an increase in hospital emergency department mentions of cocaine and heroin corresponded with a sharp decline in street prices for both drugs.1 Line-graph illustrations of the temporal relationship between drug price and emergency room mentions and the relatively large estimates of statistical correlation between the 2 trends make a compelling case that some aspects of illicit drug use may be highly responsive to changes in price. Interpretation of the data suggests that drug-related problems seen in emergency departments may be reduced by applying pressure through enforcement to drive drug prices up.

The hospital emergency department data are from the Drug Abuse Warning Network, and drug price data are from the US Drug Enforcement Agency. As Caulkins notes, the accuracy of the data from both sources is highly questionable and may vary over time.2^,3 This feature of the data would seem to be inconsistent with the large magnitude of the association (price was found to explain more than 97% of changes in emergency department drug mentions). Errors in measurement by both systems would be more likely to attenuate any estimates of association.4 The strength of the association suggests that additional factors that also exerted an influence during the study period may have been missing from the model.

A potentially important factor may be the increase in drug law enforcement efforts over the same time interval. Since 1980, there has been a nearly 3-fold increase in US federal government spending on drug enforcement.5 Chief among the unintended consequences of current drug control efforts is that drug potency may be high, contributing to unsafe use.5 Increasing drug concentration per volume benefits the seller by making the drug easier to conceal but may punish the user by making drug dosages less predictable. Drug Abuse Warning Network data would seem to be particularly susceptible to changes in drug potency, since they are based primarily on overdose cases.6 Changes in drug potency could conceivably produce the observed changes in these data even in the absence of an increase in drug use.

Caulkins raises an important public health question, which is whether adverse consequences of drug use can be reduced by efforts to increase the price of illicit drugs. However, Caulkins' data cannot provide an answer to this question. Given the massive increase in drug law enforcement efforts during a period of decreasing street drug prices, it seems unlikely that any escalation of these efforts could reverse the trend and drive street prices back down. The last 2 decades have brought the globalization of the world economy, with advances in communication, transportation, and the ability to move capital across national borders.7 Forces that have expanded global production and distribution of inexpensive consumer goods may have also led to improvements in global distribution of inexpensive psychoactive drugs.

Caulkins' article clearly indicates that it may be prudent to adapt public health strategies to the presence of cheaper and more potent illicit drugs. At the conference “Preventing Heroin Overdose: Pragmatic Approaches” (held in Seattle, Wash, January 13–14, 2000), several examples of new thinking in a changing public health environment were presented. These new approaches included teaching drug users to perform rescue breathing, distributing medications to counteract overdoses, and developing ways to reconcile conflicts between the objectives of law enforcement and the objectives of public health that may exist at an overdose scene. New ideas of this kind will be needed to surmount the public health challenges that may arise in relation to increased availability of less expensive and highly potent drugs.