Discussion
This multisite cohort study found a substantial health and economic burden of community-acquired ARI among older adults aged ≥60 years. The mean societal cost of an episode of AURI was US$13.9 and of pneumonia was US$25.6, with three-fourths of the total cost being indirect costs. The mean per capita annual cost due to symptomatic respiratory illness was equivalent to 2% of India’s per capita income and was mainly attributed to acute upper respiratory illness. Approximately 50% of pneumonia cases did not seek healthcare and most sought ambulatory care at primary level. Non-hospitalised pneumonia episodes still incurred substantial economic costs, primarily because of lost wages for both participants and caregivers. The presence of comorbidity and care seeking was associated with higher costs. Demographics, disease burden, healthcare seeking and cost of respiratory illness varied substantially between sites.
We found that health insurance coverage was low across sites, which has also been reported in the Longitudinal Aging Study in India (LASI).25 LASI has also reported 24.9% multimorbidity and 29.3% with single comorbidity in nationally representative sample from across India, which is similar to two of our sites (Ballabgarh and Pune), whereas Chennai and Kolkata reported much higher levels of comorbidity.26 Our study reported a very low treatment seeking behaviour for respiratory illness including pneumonia. Similarly, the 75th round National Sample Survey of India, 2017–2018, reported that 33.6% of the elderly went to a public outpatient care for any illness in the last 15 days.27 While there are notably substantial differences in socioeconomic conditions, a qualitative study among older adults in Canada also reported delays in seeking professional medical care due to misperceptions about the severity of community-acquired pneumonia, trying to manage illness at home and access barriers.28
It is difficult to compare our cost estimates of pneumonia among older adults as most previous studies have used hospital-based approaches or used administrative or insurance data from developed countries. We found that almost three-fourths of the cost of respiratory illness was contributed by indirect costs in our study, so studies only focusing on treatment cost would likely underestimate the true cost. In France, the mean direct medical cost of a pneumonia episode managed ambulatorily (€118.8) in primary care had equal weight for medical time, drugs, diagnostic procedures and tests.29 It also estimated the indirect cost (€1980) per ambulatory episode contributed to more than 90% of the total cost. In Japan, the median treatment costs of pneumonia were US$346 (IQR: 195–551) per outpatient episode among those above 65 years.15 Increases in the cost of a respiratory illness in participants with comorbidities have been reported in many studies, most of which are hospital based.30 In a study by Vissink et al among Dutch elderly, being male, younger and higher socioeconomic status were associated with lower costs.31
In our study, people aged more than 75 years, men, those with comorbidities, those seeking care in outpatient or inpatient, with pneumonia had higher costs. Similar results for community-acquired pneumonia have been reported before. A higher cost among inpatients, elders and individuals with comorbidities was reported by Kosar et al.32 Most studies on cost of pneumonia are from developed countries and are hospital based or based on cost estimated through insurance pay-outs. These are not relevant to our context. Chennai and Pune reported significantly higher costs and as already seen it was driven by higher indirect costs in Chennai and higher direct costs in Pune. Interestingly, once adjusted for each other, coverage with insurance, use of private sector and being wealthier did not influence the cost.
In our study, almost 80% of the total cost of pneumonia was contributed by indirect cost and cost of medicines was the major contributor of the direct cost. In a retrospective analysis of patients at a tertiary hospital, treated between October 2015 and March 2016, the main inpatient cost driver was hospital stay (94.97%), followed by medication (3.30%) and diagnostic tests (0.87%). For outpatients, key cost drivers, in order of magnitude, were prescribed medication (38.84%), diagnostic tests (33.51%) and physician visits (17.54%).33
In this study, ARI patients with laboratory-confirmed influenza incurred similar costs to those who tested negative. Antiviral use was very low, and the use of antibiotics was not related to influenza status. Respiratory illnesses often present with similar syndromes, are seldom tested for specific pathogens at the point of care and are treated empirically in the same manner. This calls for efforts to rationalise the use of antibiotics and antivirals in these patients perhaps using standardised but context-specific test and treat algorithms as these might have implications for patient prognosis as well as antimicrobial resistance. The resource utilisation and severity of illness did not vary for influenza-positive cases as compared with others. In an analysis of a cohort of 505 adult patients hospitalised with confirmed pneumonia between 2004 and 2010 in the Netherlands, detection of Staphylococcus aureus, or Streptococcus as causative pathogen and not viral pathogens were independent cost driving factors.34 The median cost of an influenza-associated outpatient visit was US$4.80 (IQR=2.93–8.11) and an influenza-associated hospitalisation was US$82.20 (IQR=59.96–121.56) in Bangladesh.35 This ratio of ambulatory to inpatient cost of 16 was much higher than our study.
The economic burden associated with pneumonia remains substantial at >US$17 billion annually in the USA.36 Applying the cost of US$25.6 to estimate of 138 million older adults (≥60 years) in India with a pneumonia incidence of 14.72 per 100 person-years as found in the study (1127 episodes in 7653 person-years of follow-up) means that pneumonia costs for India might be approximately US$520 million annually. The total economic burden of pneumonia in adults over 50 years of age was €12.6 million (Czech Republic); €9.2 million (Slovakia); €22.4 million (Poland); and 18.3 million Hungarian forint (Hungary) per year; with hospitalisation representing over 90% of the direct costs of treatment.37 A review of literature published between 1990 and May 2010 on the clinical and economic burden of CAP among adults in Asia-Pacific concluded that pneumonia is a significant health burden with significant economic impact in this region.38 Estimates from India are much lower despite a higher population because of low healthcare seeking with low rates of hospitalisation as well as lower cost of medical and non-medical resources. Among the hospitalised, however, the admission rate to intensive care unit was not very different from other studies.39
Our study estimated the total cost of pneumonia episode was US$25.6 and the annual cost of acute respiratory illness as US$29.5. The estimated total per capita annual healthcare expenditure for Indian in 2019–2020 was US$68.7, out of which 47.1% is by out-of-pocket expenditure.40 Using data from the National Sample Survey Organization, Social Consumption in Health 2018, Sriram and Albadrani estimated mean (SD) household monthly consumption expenditure for 2018 as US$132.8.41 The total cost of pneumonia episode (US$25.6) is two times the threshold used for defining catastrophic health expenditure (10% of monthly household consumption expenditure),42 indicating the potential for impoverishment in households where the elderly develop pneumonia. We did not collect data on household level income or expenditure and therefore could not estimate the proportion of household income spent on pneumonia.
The strengths of the study include a large multisite cohort size and multiple years covered. The study was community-based and used rigorous weekly follow-up visits to capture the treatment seeking, resource use and cost data. The limitations in the study include methods adopted to estimate loss of productivity and method of its valuation using national per capita income. Given that indirect costs were the main contributors to the cost, its valuation assumes importance. While three-fourths of the participants were unemployed, researchers have questioned the notion that older adults stop being productive once they retire.40 43 The minimum daily wages of the government of India vary from US$5.2 to US$11.7, depending on skill level and area of work.44 Cost of caregivers’ productivity loss constituted very small proportion of indirect costs. Overall, 57% of the caregivers were working and their mean income was US$91 per month, much less than US$155 estimate of national per capita income used in the study. Due to the community-based nature of the study (unlike facility based), resource use might not have been well captured. The cost of public facilities could have been underestimated as cost of medicines and investigations done free of charge might not have been captured.
In conclusion, the high economic burden due to respiratory illness characterised by poor insurance coverage, poor healthcare seeking as well as low vaccination coverage demonstrated in this study sites call for contemplating public health interventions to address pneumonia in this age group. The integrated public health approach would include the use of different vaccines for prevention and a case-management approach for the management of community-acquired pneumonia among older adults delivered through a strengthened primary healthcare system.