SWORD survey: Seasonal trends in hospitalisation and mortality among patients with respiratory illnesses in India

Objective: The SWORD study examined seasonal variations in respiratory disease related hospitalisations and mortality across India. It also assessed risk factors and comorbidities influencing these outcomes. Methods: This multicentre, questionnaire-based, point prevalence study was conducted across four seasonal weeks in 2017–2018. Data on respiratory admissions on the first day and deaths over the following week were collected. Results: At 245 centres, 2,886 patients were hospitalised, and 394 deaths occurred. COPD was the leading cause of both hospitalisations and deaths, followed by tuberculosis (TB), respiratory tract infections (RTI), asthma, pleural effusion, lung cancer, bronchiectasis, and interstitial lung disease (ILD). Respiratory admissions and deaths peaked in winter (28.7% and 32.7%) and were lowest in summer (21.1% and 18.0%). COPD hospitalisations were significantly higher in winter than summer (OR: 1.39; 95% CI: 1.1–1.8), with mortality showing a similar pattern. Key risk factors for hospitalisation and death varied by disease. Conclusion: Respiratory hospitalisations and deaths in India follow a clear seasonal trend, with winter posing the highest risk and summer the lowest. COPD, TB, RTI, asthma, pleural effusion, lung cancer, bronchiectasis, and ILD were the most frequent causes. These findings underscore the need for targeted, season-specific strategies to manage respiratory diseases effectively.