Risk factors for pneumococcal disease in persons with chronic medical conditions: Results from the LIFE Study

Objectives: This study aimed to identify the risk factors for pneumococcal disease. Methods: The study was performed using insurance claims data from the residents of 12 Japanese municipalities. Based on recorded diagnoses, we identified chronic medical conditions in each patient between April 2015 and March 2016 and examined the subsequent occurrence of a pneumococcal disease from April 2016 onward. Cox proportional hazards models were used to estimate the hazard ratio of each chronic medical condition for a pneumococcal disease occurrence. Results: The study was conducted on 732,235 patients, of whom, 61,306 (8.4%) were aged 0-18 years, 184,367 (25.2%) were aged 19-49 years, 126,078 (17.2%) were aged 50-64 years, and 360,484 (49.2%) were aged ≥65 years. A higher number of conditions was associated with a higher incidence of pneumococcal disease. Significant risk factors for pneumococcal disease in all patients included chronic heart disease, chronic lung disease, diabetes mellitus, cancer, and chronic renal disease. Furthermore, chronic lung disease, diabetes mellitus, aspiration pneumonia, and immunosuppressant use were risk factors among patients aged 50-64 years. Conclusions: Persons aged 50-64 years with multiple chronic medical conditions or with specific conditions are at a higher risk of developing pneumococcal disease, indicating a need to consider their inclusion in routine vaccination programs.