Strengths and Limitations:
It’s crucial to acknowledge certain limitations in the present study. First of all, the cross-sectional design of our study did not allow us to investigate the association of CRI and influenza with onset of AMI. For this inaugural Bangladeshi study, we favored a cross-sectional design, lacking a control group, over a case-control approach due to time sensitivity, the need for rapid data collection, its efficiency, cost-effectiveness, and capability to study a larger population. Therefore, in our recommendation for future research, we recognize that a case-control design would be the appropriate method to enable statistical investigation of the association of CRI and influenza with AMI. Secondly, any clinical definition for acute respiratory illness has inherent limitations including subjectivity, limited specificity, and variability of respiratory symptoms depending on the patient’s age and individual experiences, compounded by the lack of standardization. This could lead to potential bias in our prevalence estimates. A more standardized and objective measures of respiratory illness may improve the reliability and generatability of the findings. Third, we were unable to further confirm every AMI diagnosis through angiogram findings of coronary artery blockage and echocardiogram findings of regional wall motion abnormalities. Fourth, due to delay in initiation of the field implementation we had not enrolled participants during peak influenza months June-July of 2017 which might significantly affect our overall estimates for frequencies of CRI and influenza. Our study only investigated two annual influenza seasons, which may not fully reflect the broader trends of influenza prevalence among AMI patients. As influenza activity varies significantly year to year, a longer study period would yield a more comprehensive understanding of these patterns and their impact on AMI. Fifth, we utilized only qRT-PCR to identify influenza among participants which had limited sensitivity due to diminution of viral shedding. We believe addition of influenza serology would have significantly enhanced the sensitivity of the current study to identify additional influenza positive participants. Lastly as our study was conducted in a single center in Bangladesh, our results are limited due lack of generalizability and hence may not represent the broader population of the country.