In this large multicenter study across 13 tertiary PICUs in India, the Indianized Pediatric ALS tape demonstrated acceptable accuracy and reliability for weight estimation in critically ill children. Nearly 80% of children were correctly assigned to the expected color band, and 78.6% of weight estimates fell within ± 10% of measured weight. The overall mean bias was small (− 0.6 kg; 0.08%), suggesting minimal systematic error. Interrater agreement for color-band assignment was high (κ = 0.84), indicating consistent reproducibility across trained healthcare personnel.

The Broselow tape is widely recommended in PALS guidelines for weight estimation [2, 3, 13]. However, it is derived from US growth standards and has been shown to overestimate weight in Indian children [4, 5]. Overestimation may lead to excessive medication dosing and inappropriate equipment selection [11]. The present study was thus designed to address this limitation by validating a tape developed from contemporary Indian growth data [14]. Unlike strategies that apply correction factors to the Broselow tape, the current model recalibrates length demarcations for each color band while retaining the established color sequence, thereby maintaining familiarity in emergency settings. Importantly, validation was conducted in critically ill children rather than healthy outpatient cohorts, enhancing clinical relevance. Further, inclusion of both public and private institutions enhances generalizability across socioeconomic strata.

The proportion of estimates within ± 10% of measured weight (78.6%) compares favorably with published validations of length-based systems [11, 15, 16]. When grouped into lower, middle, and higher weight bands, lower bands showed modest underestimation (13.1%), middle bands minimal deviation (− 3.4%), and higher bands mild overestimation (− 10.3%). This variability likely reflects increasing heterogeneity in body composition with age, pubertal onset, and the coexistence of undernutrition and emerging obesity in Indian children [7, 8]. Despite this gradient, overall bias remained clinically acceptable.

Regional differences were observed, with concordance exceeding 90% in the South and Central zones and lower agreement in the East. This variability suggests that a “one-size-fits-all” approach may not perform uniformly across a diverse country such as India; regional refinement could be explored in future studies. Regional variability may reflect differences in nutritional status, anthropometric profiles, case-mix, and measurement practices across centers. These findings are consistent with known inter-regional differences in growth patterns and nutritional status across India [12]. Further, the minimal overall bias observed despite inclusion of nutritionally vulnerable children supports the robustness of the tool in real-world clinical settings.

Interrater reliability analysis showed good agreement. This is particularly important in emergency care, where rapid application by multiple providers is expected. Structured training sessions and periodic reinforcement may have contributed to this consistency. These findings highlight that standardized training should accompany dissemination of any length-based weight-estimation tool.

In comparison with recently published indigenous tools, the InChiTape reported that approximately 69% of critically ill children had weights within the predefined acceptable range. That model was derived using WHO growth standards for children under five years and earlier IAP references for older children. However, WHO standards may not fully reflect contemporary Indian growth patterns, particularly in older children and across diverse socioeconomic groups [9, 12]. In contrast, the present tape was developed exclusively using multicenter Indian growth data and validated in a larger cohort of critically ill children, demonstrating higher overall concordance. Additionally, a substantial proportion of participants in the InChiTape validation cohort were under five years of age, which may have influenced the overall performance estimates [15].

Beyond indigenous adaptations, newer two-dimensional weight-estimation systems, such as the Mercy method and the PAWPER tape [16, 17], incorporate both length and body habitus to improve accuracy across children with varying body compositions. Although these methods have demonstrated improved performance in several settings, differences in anthropometric profiles across populations underscore the continued need for context-specific validation.

Strengths of this study include its large sample size, multicenter representation across five geographical zones, and inclusion of critically ill children. Conducting the study under the aegis of the IAP Intensive Care Chapter adds methodological rigor and facilitates potential integration into national training frameworks. However, several limitations should be considered. Comparison with the Broselow tape was not performed in this cohort. Children outside the measurable length range (45–145 cm) and those with extreme anthropometric values were excluded, which may limit generalizability to very small neonates, taller adolescents, and severely malnourished critically ill children, and may have modestly improved observed accuracy estimates. Pubertal staging was not formally assessed and may partly explain variability in higher weight bands. In some critically ill children, measured weight was obtained after clinical stabilization or derived from recent documented clinical weights, which may have introduced minor inaccuracies due to fluid shifts or interval illness-related weight changes. Interrater reliability assessed on mannequins may overestimate real-world agreement in critically ill children with movement limitations, tubes, and monitoring devices. Although overall accuracy was clinically acceptable, the modest underestimation observed in lower weight bands and overestimation in higher weight bands may still have implications for emergency drug dosing and equipment selection, particularly in neonates and infants with narrower therapeutic margins. Finally, future studies should compare the tape directly with existing systems such as the Broselow tape and evaluate the impact of tape-guided dosing on medication errors and clinical outcomes across nutritional and regional subgroups.

In conclusion, the Indianized Pediatric ALS tape demonstrated acceptable accuracy, minimal overall bias, and strong interrater reliability in critically ill Indian children across multiple PICUs. Developed using Indian multicentric growth data, it represents a context-specific and practical tool for emergency weight estimation in diverse pediatric intensive care settings in India. Future implementation studies should evaluate the impact of tape-guided weight estimation on medication errors, equipment selection, and resuscitation efficiency.