Influenza Vaccination Rate, Awareness & Risk of Acute Exacerbation of Chronic Obstructive Pulmonary Disease (COPD): A Tertiary Care Cross-Sectional Analysis

Abstract

Background: Chronic Obstructive Pulmonary Disease (COPD) is one of the top four diseases causing a tremendous burden for the healthcare system. Recurrent exacerbations in these patients are the main problems causing significant ill health and deaths. Most of the exacerbations are caused by infections, especially rhinoviruses. The most effective way to prevent exacerbation events is yearly influenza vaccination for all persons with COPD. The reasons for non-adherence to yearly vaccination are multi-factorial; therefore evidence is needed about influenza vaccine usage among COPD patients in Pakistan.  Objective: This study was conducted with the aim of determining the yearly influenza vaccination rate, influencing factors, barriers, and its association with acute exacerbation of COPD in patients admitted to our regional tertiary care hospital. Methodology: This cross-sectional study was done on patients who were admitted with acute exacerbation of COPD at Ayub Teaching Hospital Abbottabad, Pakistan from July 2021 to June 2022. Patients were interviewed for all baseline characteristics and medical records were checked for yearly Influenza vaccination status and number of admissions with exacerbation and hospitalization during the preceding year, i.e. July 2020 to June 2021. Results: The mean age of the study participants was 59.1 (±8.1) years.  Males were 282(34.5%) and 543(68.5%) were females. Illiterate patients were 714 (86.5%), 80 (9.7%) patients had primary/matric education, and 31(3.8%) patients were BA/BSc degree holders. Over all 162(19.64%) participants received vaccine during the year. Among the vaccinated individuals 134 (82.71%) individuals received only influenza vaccine, 4 (2.47%) only pneumonia (pneumococcal) vaccine and 24(14.81%) received both influenza and pneumococcal vaccines. The frequency of vaccination was higher for BA/BSc degree holders (83.9%) than those with primary/matric education (51.3%, P < 0.05), and lowest for illiterate individuals (13.3 %, P < 0.05). Yearly Influenza vaccination reduced hospitalizations for episodes of acute exacerbation of COPD, the evidence is conclusive as 18-35% of respondents who had two or more episodes of acute exacerbation rate in last one year, the vaccination rate was quite low (0.12–0.85%). In 11-16% of respondents who had 1 or fewer episodes of yearly exacerbation rate, the vaccination rate was 9-11%.  In logistic regression analysis, the yearly influenza vaccination rate was associated with reduced hospitalization due to episodes of acute exacerbation of COPD with an adjusted odds ratio (AOR) of 0.19 (95% CI: 0.01 – 0.07). Conclusion: The yearly Influenza vaccination rate is very low in our region and is associated with a high risk of exacerbations in COPD patients. The important barrier to getting the vaccine is the lack of awareness about the influenza vaccine. Keywords:  Influenza Vaccine; Rate; Risk; Acute Exacerbation of COPD