Difference Between Incidence and Prevalence

Epidemiology is a branch of medical science that studies health events and factors in particular populations. Incidence and prevalence are two essential epidemiological measurements that estimate the possibility of the occurrence of a specific disease in a particular population.

They may look similar but are very different from each other. This article will cover the meaning of incidence and prevalence and their various differences.

Meaning of Incidence and Prevalence

Incidence

Incidence means the total number of new individuals who develop a certain disease or a specific health-related event in a particular population over a time span. And thus, it gives the rate of new diseases.

The accuracy of the incidence data relies on the accuracy of the diagnosis of the particular disease. The incidence rate can be given based on the distinct subsets of the specific population, like age, gender, diagnostic category, etc.

Prevalence

Prevalence means the total number of individuals in a specific population with a particular disease or health condition at a specific time. Thus, it includes both the new and the old cases of a disease.

It is divided into two types:- point prevalence and period prevalence.

Point prevalence: It means the number of cases at a particular time.

Period prevalence: It means the number of cases in a time, mostly 12 months.

Also Read: Difference Between Pandemic and Epidemic

Differences Between Incidence and Prevalence

Understanding the difference between prevalence and incidence can be of great use as these medical terminologies have significance for doctors and scientists. They analyze their figures to choose future action and treatment methods.

The differences can be explained with the help of the following points:-

Meaning

Incidence refers to the number of new cases of a specific disease or an injury in the population in a particular year.

Prevalence refers to the number of cases at a particular point in time.

Also Read: Difference Between Active and Passive Immunity

Types of Cases

Incidence takes only the new cases of a specific disease into consideration in the population. In contrast, in prevalence, both the old and the new cases are considered in the population.

Denominator

The denominator of incidence is just the population at risk, whereas the entire population is taken as the denominator of prevalence.

Follow-up of Individuals

Incidence needs the follow-up of individuals in a population for identifying new cases, whereas prevalence does not need a such follow-up of individuals for identifying any new case.

Disease Duration

Another dissimilarity between incidence and prevalence is that incidence doesn’t rely on the duration length of the illness, whereas prevalence relies on the duration length of the disease. And long duration will ultimately increase the prevalence of the disease.

Also Read: Difference Between Cold and Flu

Significance

Incidence calculates the rapidity of the disease occurrence, whereas prevalence calculates the ratio of the population with that particular disease.

Preference

Incidence is preferred when studying cause and effect, whereas prevalence is preferred when estimating the population-based burden of chronic disease and the implication of health services.

Use

Incidence is used to denote the rate and the risk of a specific disease in a particular population, and prevalence is used to denote how widespread a disease has become for a specific population.

Also Read: Difference Between Viral and Bacterial Tonsillitis

Conclusion

Incidence is the total number of new cases of a particular disease in a population at a specific time. And it is very vital for determining the risk of a specific disease.

Prevalence is the total number of new and old cases of a specific disease in a particular population. And it indicates how widespread the disease is in a specific population.

Therefore, prevalence and incidence are related yet are two different measures of the distribution of a specific disease in a particular population.