The public health model emphasizes the overall health of the public. In contrast, traditional healthcare focuses on the health of one individual. Public health uses a three-prong approach to prevention and intervention. This is known as "the agent, the host, and the environment." Threats to public health require: 1) a susceptible host (e.g., a person) 2) an infectious agent, and 3) a supportive environment (meaning an environment that makes the spread of infection possible such as unsanitary or unsafe living conditions). The public health model originally developed his 3-sided triangular model for infectious disease. The model now includes addictions.
According to the public health model, interventions may target any part of this triangle and we would expect public health to improve. . For example, an addiction prevention strategy that targets "the host" (a person) teaches children "refusal skills." These skills reduce their susceptibility to addiction. An intervention aimed at the infectious agent (drugs) is to control access to drugs (laws that regulate alcohol and tobacco). Conversely, we could limit exposure to drugs by making them illegal and difficult to obtain. An intervention targeting the environment is a public health campaign that strives to change people's attitudes towards gambling.
Harm reduction is a specific type of public health strategy. Harm reduction is more applicable to drugs and alcohol than activity addictions. Harm reduction accepts that it is not possible to eliminate addiction. Instead, the public health goal becomes reducing the harmful effects of addiction. Because addiction affects both individuals with addictions and their communities, harm reduction seeks to reduce harm through any means necessary. The goal is an overall improvement in public health. For instance, IV drug users who become HIV+ can spread this disease to addicts and non-addicts alike. A harm reduction approach could be a needle exchange program (providing free, clean needles to IV drug users). People who abuse alcohol can kill someone with their car. A harm reduction approach might be a public health campaign that encourages the use of a sober "designated drivers." This approach accepts that people will get drunk but reduces harm by providing an alternative to drunk driving.
Other, more controversial examples of the harm reduction approach are methadone maintenance programs and drug consumption rooms. Methadone maintenance programs provide heroin addicts an oral dose methadone to replace IV heroin use, at a supervised medical clinic. Some European nations are experimenting with drug consumption rooms. Here, IV drug users can go to use their own drugs. They receive clean needles and medical monitoring while they are using drugs. These harm reduction strategies have several public health goals: 1) To substitute high risk drug use, with more hygienic, lower risk drug use, 2) To reduce morbidity, mortality, while promoting the long-term health of users and the general public, and 3) To reduce crime and public nuisance associated with drug use.
In the public health model, recovery consists of intervening at any level (host, agent, or environment) in varying degrees, as needed.