Morbidity and mortality are both common variables used in statistics related to a wide variety of health topics. Each disease or health condition can be assessed through measures of incidence and prevalence in various groups of the population. These markers are often mentioned in conjunction or in the same context. However, morbidity and mortality rates define distinct sides of the discussed issue, and should not be used interchangeably.
The notion of morbidity accounts for the condition of being ill or having specific health problems, including acute and chronic illnesses. A broken arm, stroke, diabetes, Alzheimer’s disease, and cancer are examples of morbidity. An individual can live many years having one or a few morbidities. In contrast, mortality relates to the death itself and usually appears in scientific literature as a number of deaths in a population over a period of time, either in general or due to a particular health issue. Importantly, morbidity does not always lead to mortality. For example, an individual can have diabetes, receive proper medical support, and live his or her whole life almost unaffected in terms of the overall level of well-being.
At a national level, morbidity and mortality data are collected and calculated by the Centers for Disease Control and Prevention. Morbidity rate within a population is measured by the prevalence of a certain disease or health condition. Similarly, the number of deaths due to a disease divided by the total amount of people generates a mortality rate. For instance, the mean estimated incidences of Stevens-Johnson syndrome were 9.2 per million adults per year throughout 2009-2012 in the US (Hsu, Brieva, Silverberg, & Silverberg, 2016). Mean adjusted mortality for the same condition was 4.8% (Hsu et al., 2016). These rates are connected but contain different information.
Mortality rate calculated for each condition also allows finding another significant marker of population health – leading causes of death. Such data is used in the development of intervention strategies on a national level, highlighting important issues and possible ways of improvement. In particular, leading causes of death in the United States during 1999-2014 were “heart disease, cancer, unintentional injury, chronic lower respiratory disease, and stroke which together accounted for 1,622,304 deaths (approximately 62% of all deaths) in 2014” (Moy et al., 2017). That means that four of the five leading causes of death were chronic diseases.
Such a marker could vary in other counties. In comparison, in Bangladesh, leading causes of mortality for women in 2010 were age-related disease (102.8 per 100,000 people), blood pressure and heart disease (76.76) followed by asthma and respiratory disease (41.24) (Moon & Kamruzzaman, 2018). In the case of men, principal causes of death were asthma, blood pressure, heart diseases (130.1), and old age complication (102.7) (Moon & Kamruzzaman, 2018). This difference in leading causes of death between countries can be explained by many specific factors, including economic, environmental, genetic, and others.
In conclusion, both morbidity and mortality rates provide valuable insight into hidden relationships between health conditions and deaths in the context of other confounding factors. Morbidity relates to the illness itself, whereas the mortality rate signifies the number of deaths caused by this illness. The mortality data can also emphasize the leading causes of death within a defined population. These markers contain vital information for disease management and control highlighting distinct sides of the problem. Therefore, morbidity and mortality rates should be used in compliance with their differences and objectives.
References
Hsu, D. Y., Brieva, J., Silverberg, N. B., & Silverberg, J. I. (2016). Morbidity and mortality of Stevens-Johnson syndrome and toxic epidermal necrolysis in United States adults. Journal of Investigative Dermatology, 136(7), 1387-1397. Web.
Moon, M. P., & Kamruzzaman, M. (2018). Mortality experience trends in Bangladesh: Present and past facts. Humanity & Social Sciences Journal, 13(2), 11-20. Web.
Moy, E., Garcia, M. C., Bastian, B., Rossen, L. M., Ingram, D. D., Faul, M., … Iademarco, M. F. (2017). Leading causes of death in nonmetropolitan and metropolitan areas – United States, 1999-2014. Morbidity and Mortality Weekly Report, 66(1), 1-8. Web.