Can harm ratings be useful?

Comparative risk assessment of alcohol, tobacco, cannabis and other illicit drugs using the margin of exposure approach

A comparative risk assessment of drugs including alcohol and tobacco using the margin of exposure (MOE) approach was conducted. The MOE is defined as ratio between toxicological threshold (benchmark dose) and estimated human intake. Median lethal dose values from animal experiments were used to derive the benchmark dose. The human intake was calculated for individual scenarios and population-based scenarios. The MOE was calculated using probabilistic Monte Carlo simulations. The benchmark dose values ranged from 2 mg/kg bodyweight for heroin to 531 mg/kg bodyweight for alcohol (ethanol). For individual exposure the four substances alcohol, nicotine, cocaine and heroin fall into the "high risk" category with MOE < 10, the rest of the compounds except THC fall into the "risk" category with MOE < 100. On a population scale, only alcohol would fall into the "high risk" category, and cigarette smoking would fall into the "risk" category, while all other agents (opiates, cocaine, amphetamine-type stimulants, ecstasy, and benzodiazepines) had MOEs > 100, and cannabis had a MOE > 10,000. The toxicological MOE approach validates epidemiological and social science-based drug ranking approaches especially in regard to the positions of alcohol and tobacco (high risk) and cannabis (low risk).

Quantitative damage-benefit evaluation of drug effects: major discrepancies between the general population, users and experts

AIMS

This study sought to quantify the perceptions of damage and benefit, for users and society, associated with five addictive substances (alcohol, tobacco, cannabis, cocaine and heroin) and one addictive behavior (gambling), in a large sample representative of the French population. We compared with expert assessments and investigated the effects of substance consumption on these perceptions.

FINDINGS

The ranking of substances by the lay public is very divergent from that of experts. The public overestimates damage to users and to society and underestimates the benefit, in comparison with experts, for all substances. Alcohol is the only exception, with damage and benefit perceptions similar to those of experts. Heroin and cocaine are perceived as the two most dangerous substances. The damage of cannabis and alcohol are judged to be equivalent. The three legal substances are associated with the highest overall benefit, although cannabis has the highest perceived benefit for users. Substances with the highest perceived benefit tend to be associated with perception of lower levels of damage. Individuals with an history of substance use have a perception of the damage and the benefit for that substance which is more congruent with experts, including a similar ranking of substances.

CONCLUSIONS

Prevention campaigns focused on perceptions of damage alone have reached their limits. The perception of benefit should be taken into account in early interventions with illegal substance users.

Drug, sex and age differentials in the use of Australian publicly funded treatment services

Context:

Little is known about the proportion of the Australian population using alcohol or other drugs who may seek treatment. There is a need to have some additional estimates of population morbidity which reflect harms associated with use.

Objective:

To determine Australian population rates of publicly funded community based specialised alcohol and other drug treatment and in-patient hospital care by those ‘at risk’, by drug type, sex and age.

Design and setting:

The design is secondary data analysis of publicly available datasets. We use the latest available complete data on Australian general population incidence of alcohol, cannabis amphetamines and ecstasy use (2007 National Drug Strategy Household Survey) and nationally collected administrative data on publicly funded specialised alcohol and other drug treatment services (2006–2007 Alcohol and Other Drug Treatment Services National Minimum Dataset) and public hospitals (2006–2007 National Hospital Morbidity Minimum Dataset) to calculate rates of drug treatment and in-patient hospital care per 1000 Australians. ‘At risk’ for alcohol is defined as being at risk of short term harm, as defined by the National Health and Medical Research Council (2001). ‘At risk’ for illicit drugs is defined as those exposed to potential harm through at least weekly use of cannabis, amphetamines and ecstasy use.

Results:

Risky alcohol consumption followed by recent cannabis use appears to lead to most harm. Greater harm seems to be experienced by males rather than females. Younger adults (15–19 years) and older adults (40+ years) seem also to experience the highest rates of harm.

Conclusions:

It is possible to derive population estimates of harms associated with licit and illicit drugs use. Treatment rates vary across drug type, gender and age. Alcohol and cannabis are the substances whose use leads to the greatest demand for services. Ecstasy appears to generate few presentations for treatment. Publicly available data can be used to estimate harms associated with the use of particular substances. Such estimates are best interpreted in the light of other ways of estimating harms.