“The population strategy of prevention operates through the medical services at the level of the proximal causes of illness, but has to operate on a much wider base in order to confront those far more potent underlying influences, ‘the causes of causes’.”
– Geoffrey Rose, The Strategy of Preventive Medicine.
It is clear that social conditions affect health, and social epidemiology aims to understand the mechanisms through which social conditions exert their effects and to identify factors amenable to interventions to improve population health. However, since social conditions are often not easily manipulated, health promotion strategies typically focus on the more proximal causes of disease and ill health, in lieu of the more daunting social causes. This tendency to substitute the near causes rather than the root causes was the impetus for Geoffrey Rose to highlight the need for epidemiology re-focus prevention efforts on ‘the causes of causes.’
Geoffrey Rose, in his influential book “The Strategy of Preventive Medicine” explained that disease could either affect a minority of the population with a rare exposure (e.g. exposure to high doses of ionizing radiation among persons treated for leukemia) or an entire population through a ubiquitous exposure (e.g. exposure to alcohol). In each case, Rose argued that a different prevention approach was necessary—a individualized approach that targets the exposure in the former and a broader, population-based approach in the latter. To operationalize this two-pronged approach to prevent a given disease, epidemiology must first identify the rarity or ubiquity of an exposure within the population of interest.
In a new study led by Columbia University researchers, Rose’s approach to disease prevention was applied to investigate sociodemographic and drug use characteristics of U.S. populations who report nonmedical use of prescription opioids (NMUPO) in the presence or absence of major depression.
The nonmedical use of prescription opioids represents a substantial health burden in the US. In 2013, an estimated 6.5 million Americans aged 12 or older reported using prescription opioids nonmedically in the past year. Recent epidemiologic studies have shown that NMUPO and major depression frequently co-occur, and that comorbid forms of drug use and mental illness, such as NMUPO and major depression, pose a greater disease burden than either condition alone. Therefore, in an effort to develop more tailored efforts to reduce NMUPO and related harm, David Fink and colleagues set out to identify the shared and unique characteristics of individuals reporting NMUPO in the presence or absence of comorbid depression. With Rose’s two-pronged approach to prevention as a guide, the authors proposed that the identification of shared characteristics among those reporting NMUPO in the presence or absence of comorbid major depression would suggest that a more population-based approach should be implemented. This strategy would reduce both NMUPO and major depression, whereas the identification of distinguishing characteristics for each population would suggest the need for a more individualized prevention strategy.
The population-based study, published in the Journal Drug and Alcohol Dependence, used data from the 2011 and 2012 National Survey on Drug Use and Health (NSDUH) to investigate sociodemographic and substance use differences among individuals who had a positive screen for either past-year major depressive episode (MDE) without NMUPO (MDE-alone), NMUPO without MDE (NMUPO-alone), and both NMUPO and MDE compared to those with neither NMUPO nor MDE. The study had 3 central findings. First, females were more likely than males to report both MDE-alone and comorbid NMUPO and MDE (compared to neither NMUPO nor MDE), whereas adult men were marginally more likely to report NMUPO-alone. Second, polydrug use and alcohol use disorders were more pronounced among those with comorbid NMUPO and MDE than persons with either NMUPO-alone or MDE-alone. Finally, persons with independent and comorbid NMUPO and MDE were more likely to report lower income and to be unemployed.
Overall, the study found that independent and comorbid NMUPO and MDE were disproportionately clustered with burdens of lower socioeconomic position. This suggests that a population-based approach to address NMUPO would target these social determinants of health, whereas an individualized approach to prevention should be tailored to females experiencing major depressive symptoms and polydrug users.
Article: Fink DS, Hu R, Cerdá M, Keyes KM, Marshall BDL, Galea S, Martins SS. Patterns of major depression and nonmedical use of prescription opioids in the United States. Drug and Alcohol Dependence. in press. doi: 10.1016/j.drugalcdep.2015.05.010.
Reference: Rose, G. (1992). The strategy of preventive medicine. The strategy of preventive medicine.
