Acute pancreatitis (AP) is among the most common gastrointestinal causes of emergency hospitalisation worldwide, and its incidence has been rising in parallel with increases in alcohol consumption, metabolic syndrome and hypertriglyceridaemia.^1,2 The revised Atlanta classification of 2012 defines the condition by the presence of two of three criteria — characteristic epigastric pain, serum amylase or lipase at least three times the upper limit of normal, and consistent cross-sectional imaging — and grades severity as mild, moderately severe or severe according to the presence and duration of organ failure and local complications.^3,4 Mortality is approximately 1% overall but approaches 20–30% in severe disease, and the outcome of an individual episode is determined substantially by how early severity is recognised and appropriate care instituted.⁵

The epidemiological profile of AP in India differs materially from that reported in Europe and North America. Whereas Western series describe a peak incidence in the fifth and sixth decades with a relatively balanced sex distribution and a substantial biliary contribution, Indian tertiary-centre cohorts have repeatedly described a younger, predominantly male population in whom alcohol is the dominant aetiology.⁶ Population-level incidence figures for India remain unavailable, and much of what is known derives from single-centre observational series.⁷ This demographic divergence matters directly for prognostic scoring, because several widely used instruments incorporate age as a scored variable and were derived in older populations.

Severity prediction instruments fall broadly into two families. Clinical and physiological scores — Ranson's criteria, the Acute Physiology and Chronic Health Evaluation (APACHE) II, and the Bedside Index for Severity in Acute Pancreatitis (BISAP) — draw on vital signs, laboratory values and mental status.^8,9 Radiological scores — the CT severity index of Balthazar and the modified CT severity index (mCTSI) of Mortele — quantify pancreatic morphology, necrosis and extrapancreatic complications.^10,11 BISAP, described by Wu and colleagues in 2008, has attracted particular attention because all five of its components (blood urea nitrogen above 25 mg/dL, impaired mental status, systemic inflammatory response syndrome, age above 60 years, and pleural effusion) are obtainable at the bedside within 24 hours of admission, without imaging or specialised assay.^12,13

The practical appeal of a bedside score is greatest precisely where radiological resources are scarcest. Contrast-enhanced CT requires iodinated contrast, imposes a radiation burden, is optimally performed only after 72 hours from symptom onset, and in much of rural India is either unavailable or unaffordable at the point of first contact. Jingoniya et al. made this argument explicitly, proposing BISAP as a safe substitute for CT-based severity estimation where imaging access is restricted by cost or availability.¹⁴ Yadav et al., reporting from a tertiary centre in east-central India serving an economically disadvantaged population, similarly emphasised the value of a score computable within 24 hours of presentation.¹⁵ Whether such substitution is defensible depends on how tightly the bedside score tracks the radiological reference — a question best addressed not by dichotomised accuracy alone, but by examining the strength and shape of the underlying continuous relationship.

Published correlation data in Indian cohorts remain limited, and almost none characterise performance in the specific demographic that dominates presentation in north Karnataka. We therefore undertook this study with two aims: to describe the clinico-radiological profile of AP at a government tertiary centre in this region, and to quantify the relationship between BISAP and mCTSI as continuous and stratified variables, including its magnitude, direction, linearity and the proportion of radiological variance it explains.

A hospital-based prospective observational study was conducted in the Department of General Medicine, Ballari Medical College and Research Centre (Vijayanagar Institute of Medical Sciences), Ballari, Karnataka. The institution is a government tertiary teaching hospital serving a largely rural and economically disadvantaged catchment in north Karnataka. Data collection extended from June 2022 to December 2023, a period of eighteen months. Participants. Consecutive patients admitted through casualty with AP were screened. Diagnosis required at least two of: characteristic epigastric abdominal pain with or without radiation to the back; serum amylase or lipase elevated to at least three times the upper limit of normal; and imaging consistent with AP, in accordance with the revised Atlanta classification.³ Patients above 15 years of age were eligible for inclusion. Patients were excluded if aged 15 years or below; if they had pre-existing chronic kidney disease, since elevated blood urea nitrogen of renal origin would artefactually raise the BISAP score; if the presentation represented acute-on-chronic pancreatitis; or if admission occurred more than 24 hours after symptom onset, which would invalidate the 24-hour BISAP window. Data collection. A structured case proforma captured demographic details, presenting complaints (abdominal pain, vomiting, fever, abdominal distension, breathlessness, altered sensorium, reduced urine output), duration and character of pain, history of alcohol consumption with quantity and duration, gallstone disease, prior similar episodes, comorbidities including diabetes mellitus, hypertension, coronary artery disease and chronic kidney disease, and drug history relevant to pancreatitis. General physical examination recorded pallor, icterus, cyanosis, clubbing, lymphadenopathy and oedema, together with pulse rate, blood pressure, respiratory rate and temperature. Abdominal examination specifically sought periumbilical (Cullen's) and flank (Grey Turner's) discolouration, epigastric tenderness and guarding, organomegaly, shifting dullness and bowel sounds. Investigations comprised complete blood count with peripheral smear, serum amylase and lipase, renal function tests, chest radiography, abdominal ultrasonography and CECT of the abdomen and pelvis. Index measurement. BISAP was calculated within 24 hours of admission, assigning one point each for blood urea nitrogen above 25 mg/dL, Glasgow Coma Scale below 15, systemic inflammatory response syndrome (two or more of temperature < 36 °C or > 38 °C, respiratory rate > 20/min or PaCO₂ < 32 mmHg, pulse > 90/min, white cell count < 4,000 or > 12,000 cells/mm³ or > 10% bands), age above 60 years, and pleural effusion on chest radiography, giving a composite score of 0 to 5.^12,13 Radiological measurement. CECT of the abdomen and pelvis was performed on days 3 to 7 of admission and scored using the mCTSI of Mortele et al.¹¹ Pancreatic inflammation contributed 0, 2 or 4 points; pancreatic necrosis 0 points for none, 2 for ≤ 30% and 4 for > 30%; and any extrapancreatic complication (pleural effusion, ascites, vascular or parenchymal complication, gastrointestinal involvement) 2 points. Totals of 0–2, 4–6 and 8–10 were classified as mild, moderate and severe respectively. Reporting radiologists were blinded to BISAP. Sample size. Using n = Z²α · P(1 − P) / d² with Zα = 1.96, an expected population proportion of 4.1% from a prior Indian study and an absolute permissible error of 6%, the minimum requirement was 48 cases; 50 were enrolled. Statistical analysis. Analysis used IBM SPSS Statistics for Windows version 29.0. Categorical data were expressed as frequencies and percentages and continuous data as mean ± standard deviation. The association between BISAP and mCTSI was quantified by Pearson's product-moment correlation and, because both variables are ordinal, corroborated by Spearman's rank correlation. Simple linear regression modelled mCTSI as a function of BISAP, reporting the slope with its 95% confidence interval and the coefficient of determination. Mean mCTSI was compared across BISAP strata (0, 1, 2, ≥ 3; the topmost strata were collapsed because of small cell counts) by one-way analysis of variance with Bonferroni correction for pairwise comparisons, and a test for linear trend was applied. Ages of patients with and without radiologically severe disease were compared by independent-samples t test. A two-sided p value below 0.05 was taken as significant. Ethics. Institutional Ethics Committee approval was obtained from Vijayanagar Institute of Medical Sciences, Ballari (Approval No. 50/PG Thesis/2021-22, dated 27 January 2023), and written informed consent was taken from all participants.

Demographic profile

Table 1. Demographic characteristics of the study population (n = 50)

The demographic signature of this cohort is its most conspicuous feature. Mean age was 33.82 years, more than a decade below the fifth-to-sixth-decade peak described in Western epidemiology, and a third of patients were under 30. Only one patient in fifty was female. Critically, no patient reached the 60-year age threshold, so this BISAP component contributed zero points across the entire cohort and the effective range of the score was 0–4 rather than 0–5.

Distribution of severity scores

Table 2. Distribution of BISAP scores (n = 50)

Table 3. Distribution of modified CT severity index scores and Mortele severity categories (n = 50)

Ninety percent of patients scored 2 or below on BISAP, while 78% fell into the moderate radiological band. The distributions are therefore both narrow, and the resulting restriction of range should be borne in mind when interpreting correlation magnitude — restricted range attenuates rather than inflates correlation, so the observed association is likely a conservative estimate.

Relationship between BISAP and mCTSI

Table 4. Correlation and regression of mCTSI on BISAP (n = 50)

The fitted model was mCTSI = 3.86 + 1.26 × BISAP. Each additional BISAP point was associated with an increase of approximately 1.26 points in mCTSI, and the score accounted for 43.1% of the variance in radiological severity. The close agreement between the Pearson and Spearman coefficients (0.657 and 0.692) indicates the relationship is monotonic and not driven by a small number of extreme observations.

Graded relationship across BISAP strata

Table 5. Mean modified CT severity index across BISAP strata

One-way ANOVA F(3,46) = 11.95, p < 0.001; test for linear trend p < 0.001.

The stepwise ascent of mean mCTSI from 3.60 at BISAP 0 to 8.00 at BISAP ≥ 3 constitutes a clear dose–response relationship and is the most clinically interpretable finding of the study. No patient with a BISAP score of zero had radiologically severe disease, whereas four of five patients scoring 3 or more did. Between these extremes, the intermediate strata carried an intermediate and largely overlapping risk of 11.8% and 16.7% respectively, indicating that BISAP scores of 1 and 2 do not usefully separate from one another and that the discriminative value of the score is concentrated at its extremes.

Age and severity

Patients with radiologically severe disease were significantly older than those without (39.0 ± 10.2 versus 32.7 ± 7.1 years; p = 0.031), notwithstanding that none reached the 60-year cut-off used by BISAP. Age therefore carried genuine prognostic information in this cohort that the score, as conventionally specified, was unable to capture.

This study describes acute pancreatitis in a north Karnataka tertiary centre as a disease of young men — mean age 33.82 years, 98% male, none above 60 — and demonstrates a strong, monotonic, graded relationship between bedside BISAP scoring and radiological severity measured by mCTSI. The correlation was significant and substantial (r = 0.657, ρ = 0.692, p < 0.001), regression indicated a rise of 1.26 mCTSI points per BISAP point, and mean mCTSI ascended stepwise across BISAP strata from 3.60 to 8.00 (p < 0.001). The demographic profile diverges sharply from Western epidemiology and from several Indian series. Gupta et al. reported a mean age of 46.49 ± 14.11 years with women outnumbering men roughly threefold, a profile consistent with predominantly biliary aetiology.¹⁶ Our near-total male predominance and younger age distribution instead point to alcohol-associated disease, an inference supported by the recognised requirement of some years of sustained heavy consumption before alcohol-related pancreatitis manifests, and by regional patterns of alcohol use. Yadav et al., studying an economically disadvantaged population in east-central India, described a comparably young male-weighted cohort.¹⁵ The clinical implication is that severity-scoring instruments validated in older, biliary-predominant populations may not transfer unmodified. The most consequential structural finding is that the age criterion of BISAP was inert throughout this cohort. With no patient above 60 years, one of five components could never be scored, compressing the attainable range to 0–4 and reducing the resolution of the instrument at precisely the point where discrimination matters. That older patients within our cohort nonetheless had significantly higher radiological severity (39.0 versus 32.7 years, p = 0.031) suggests that age remains prognostically informative below the conventional threshold, and that a lower or continuous age term might improve performance in young-onset populations. This is a specific, testable modification rather than a general call for further research. The strength of the observed correlation is comparable with, and at the upper end of, published estimates. Nie et al., comparing BISAP with mCTSI in hyperlipidaemic acute pancreatitis, found BISAP a useful prognostic indicator and reported a favourable correlation with triglyceride levels and disease severity.¹⁷ Chatterjee et al. concluded that BISAP was comparable to APACHE II and mCTSI in accuracy while being considerably simpler to calculate, and recommended it for early triage and referral to a high-dependency unit.¹⁸ Subramanian et al. likewise concluded that BISAP identifies patients at high risk within the first 24 hours of admission, before organ failure becomes manifest.¹⁹ Set against these, Gupta et al. and Harshit Kumar and Griwan found radiological and APACHE II scoring respectively superior to BISAP for predicting complications and mortality,^16,20 a divergence attributable in part to differences in reference standard and cohort composition. Interpretation requires caution on several fronts. Both variables were narrowly distributed — 90% of BISAP scores were 2 or below and 78% of mCTSI values fell in the moderate band — and such range restriction attenuates correlation, so the true association may exceed our estimate. Conversely, R² of 0.431 means that more than half the variance in radiological severity remains unexplained by BISAP, which is expected given that the two instruments measure different constructs: systemic physiological derangement versus pancreatic and peripancreatic morphology. Aetiology was not systematically classified, so the inference of alcohol predominance rests on demographic pattern rather than direct measurement. The single female participant precludes any comment on sex differences. Finally, we recorded no clinical outcomes — organ failure, intensive-care admission, length of stay or mortality — so the analysis establishes concordance between two severity indices rather than the ability of either to predict what happens to patients.

Acute pancreatitis at this north Karnataka tertiary centre affected a distinctly young and almost exclusively male population, with a mean age of 33.82 years and no patient above 60. Within this cohort, bedside BISAP scoring showed a strong graded relationship with radiological severity: each additional BISAP point corresponded to approximately 1.26 points of mCTSI, mean mCTSI rose monotonically from 3.60 at BISAP 0 to 8.00 at BISAP ≥ 3 (p < 0.001), and the score explained 43.1% of the variance in radiological severity. No patient scoring zero had severe disease, while four of five scoring 3 or more did. These findings support the use of BISAP as an interim severity estimate at the point of first contact where contrast-enhanced CT is delayed, unaffordable or unavailable, while indicating that the score's age criterion is structurally uninformative in young-onset populations and that locally recalibrated thresholds warrant formal evaluation. Larger multicentre studies incorporating aetiological classification and clinical endpoints are required to establish whether bedside scoring can safely defer or direct radiological assessment.

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