Authors’ response

Sir,

We sincerely thank the author(s) of the Letter-to-Editor¹ for their thoughtful reading of our article² published in the June 2025 issue of Indian Journal of Medical Research and for the constructive comments. We appreciate the opportunity to clarify certain methodological and analytical aspects of our study. With regards to the study design, we acknowledge the observation concerning daily monitoring of patients, however, individuals were observed during their ICU stay for the detection of medical device–related adverse events, the study was indeed cross-sectional in nature, as data were collected within a defined study period without longitudinal follow up beyond hospitalization, consistent with standard epidemiological definitions of cross-sectional studies.³ The term ‘monitored daily’ reflects active surveillance during admission and should not be interpreted as a longitudinal cohort design.³ The study was exploratory and descriptive, conducted as part of an institutional materiovigilance surveillance initiative. A formal sample size calculation was not performed due to the lack of prior local data on device-related adverse events in respiratory ICUs, which is a recognized limitation in emerging surveillance domains.⁴ All eligible patients admitted during the study period were included through convenient sampling, a commonly employed approach in hospital-based surveillance studies.⁵ Adverse events were identified through routine ICU practices involving doctors and nursing staff across shifts, aligning with recommended passive and active surveillance models.⁴ Causality assessment was performed in accordance with the operational guidelines of the Materiovigilance Programme of India (MvPI)⁴. The five-point scale applied in our study reflects MvPI recommendations for the assessment of medical device adverse events.⁴ We agree that explicit citation of the guideline would have enhanced clarity. Regarding Table III, we acknowledge that the title may appear misleading. However, the analysis was intended to explore associations between patient characteristics and reported MDAEs, stratified by gender. We also acknowledge that certain adverse events, such as ventilator-associated pneumonia or catheter-associated infections, may overlap between opportunistic infections and procedural factors. Such overlap is well recognized in critical care literature.⁶ For clarity, classification was based on the primary suspected mechanism, though such overlap is possible in routine clinical practice.⁶ With respect to Table II, the total study population comprised 90 patients who experienced 152 adverse events. An individual patient could experience more than one adverse event, a phenomenon commonly observed in ICU-based safety studies.⁷ Several events listed represent clinically relevant complications associated with device use in ICU settings. BiPAP and CPAP were presented separately to reflect real-world reporting practices, although we acknowledge that they are modes of non-invasive ventilation.⁸ We also agree that the expansion of BiPAP in the footnote contains a typographical error. Overall, we strongly believe that the crux of finings of our original study and resulting observations will help refine future studies and strengthen reporting practices in medical device safety surveillance.