Healthcare utilization has repeatedly been observed to decrease during the COVID-19 pandemic [16, 17]. Iran, as one of the countries with a high incidence of COVID-19, was found to be similarly affected, with steep reductions in the rate of hospitalizations, particularly early in the pandemic. It is plausible that a proportion of these reductions in medical admissions were for circumstance that could appropriately be managed at home [22]. However, such reductions in the number of hospital visits may also have dangerous consequences for some patients. It is well established that prompt diagnosis and treatment are important for public health and treatment delay is a predictor of adverse outcome [9].
Our study indicates that hospital admissions fell dramatically with the onset of the COVID-19 pandemic for all of nine non-COVID-19 diseases investigated, including infectious and parasitic diseases, neoplasms, mental and behavioral disorders, diseases of the nervous system, diseases of the circulatory system, diseases of the respiratory system, diseases of the digestive system, diseases of the genitourinary system, and pregnancy, childbirth and the puerperium. Our results demonstrate a sharp and significant decrease in hospitalizations in the first month after the COVID-19 outbreak, which is consistent with previous studies in other countries [6,7,8, 16, 17]. A recent WHO survey looked at the extent of the disruption of services for the prevention and treatment of non-communicable diseases [23]. One study in China showed that total healthcare expenditure and frequency of healthcare utilization decreased in medium-risk and high-risk cities during and after the COVID-19 outbreak [24]. Furthermore, in a nationwide survey carried out in Italy, De Rosa and colleagues demonstrated that hospitalizations for myocardial infarction during the COVID-19 pandemic were halved compared with the equivalent period of the previous year [13].
Supply-side factors clearly contributed substantially to the sharp decline in hospitalizations and health service utilization for non-COVID-19 diseases. Initial lack of knowledge of the COVID-19 virus and reduced capacity within hospitals due to the substantial number of COVID-19 patients requiring hospital treatment, reduced the ability of hospitals to address non-COVID-19 health disorders, with non-urgent treatments being cancelled and delayed and resources reallocated to fighting the virus [24].
Demand-side factors are also likely to be important, with patients and their family members choosing not to seek treatment or attend hospital for fear of getting infected with the virus [17, 25] or as a result of lockdown restrictions [24]. For example, we observed that the hospitalization rate for certain infectious and parasitic diseases has decreased more than twice in the first month after the pandemic compared to latest months included in the study). A study in Hong Kong [24], for example, indicated that patients waited longer before seeking healthcare during the COVID-19 pandemic compared with the same period before the pandemic. In a study of 44,000 participants conducted in Belgium after the COVID-19 outbreak, the number of people reporting fear of contagion, anxiety or a depressive disorder had increased substantially compared to a survey conducted before pandemic [26].
Similar results have been found in relation to other viruses, with studies analysing health information system data from Liberia, Guinea and Sierra Leone during the Ebola virus outbreak [27,28,29] demonstrating a significant decrease in the delivery of maternal, child and reproductive health services, interruptions in HIV and tuberculosis testing, and large-scale reductions in vaccine and malaria case management programs. This illustrates that the negative impact on healthcare utilization is not unique to COVID-19, but is more broadly relevant to epidemics of infectiour diseases. Therefore, policymakers and health care providers must design and implement appropriate and effective policies not only for the current pandemic, but also for any future crises to ensure critical healthcare services remain accessible for all diseases.
An interesting finding from the current study was the significant increases seen in the monthly rates of hospitalizations after the COVID-19 outbreak for neoplasm disease, diseases of the digestive system, and pregnancy, childbirth and the puerperium disease. This finding is not consistent with the results of previous studies. For example, Hartnett et al. [11] found that the largest declines in hospitalisations were for abdominal pain and other digestive or abdominal signs and symptoms, compared to our findings of a significant increase of hospitalizations for diseases of the digestive system.
The significant increase in hospitalizations for some disease identified in our study may be partly related to side effects of coronavirus. Previous studies have indicated that gastrointestinal symptoms, anorexia, diarrhea, nausea, and vomiting, abdominal pain and gastrointestinal bleeding are clinical symptoms of COVID-19 thus the increases demonstrated in the current study may be related to the treatment of COVID-19 [30,31,32]. In addition, these increases may be related to risk factors for hospitalization from COVID-19. For example, a large cohort study in the United States, which included population-level data from 91,412 women, revealed that pregnancy was associated with a significantly increased chance of hospitalization from COVID-19 [33]. Also, the majority of studies have shown that the risk of severe COVID-19 in pregnancy appears to be no greater than for the general population [34,35,36] and it can affect fear of infection among this groups.
Although the present study provides robust evidence of the association between the COVID-19 pandemic and hospitalization rates in Iran, there were several limitations which should be acknowledged. First, the data in this study were collected in only one region of the country and thus the generalizabity of the study findings are limited. Second, based on the observational period studied, we are not able to examine the longer-term trends in hospitalization rate changes for the diseases included in the study. Thirdly, the study focused only on public sector hospitals as we did not haveaccess to data on hospitalization rates in private and social security hospitals. Thus these results may not be generalizable to all hospitals in the region.