Routine laboratory composite indices and geriatric multisyndrome burden: a head to head evaluation against serum...

Routine blood tests are often combined into composite indices meant to summarize nutritional, inflammatory, or metabolic status in a single value. Whether these indices reflect the broad syndrome burden seen in geriatric outpatients is unclear, since most of the supporting evidence comes from oncological or surgical cohorts.

We reviewed the records of 289 patients seen consecutively at a geriatric outpatient clinic over an approximately one-year period and calculated thirteen indices from the first available laboratory panel. The outcome was multisyndrome burden, scored across ten geriatric syndromes, with a burden of four or more defined as high. Each index was entered into a separate logistic regression adjusted for age, sex, comorbidity, and polypharmacy, and the thirteen p-values were corrected for multiple testing with the Benjamini-Hochberg procedure.

Only the Prognostic Nutritional Index (PNI) and the HALP score remained associated with high burden after correction (adjusted odds ratio per standard deviation 0.55 and 0.64, respectively); none of the inflammatory or metabolic indices reached significance in the full cohort, although the neutrophil-to-lymphocyte ratio and the systemic immune-inflammation index did so in the subgroup in whom all ten components were assessed. Removing the two activity-of-daily-living measures from the outcome left neither association significant, which places the relationship mainly on functional status rather than on an independent inflammatory pathway. Neither index discriminated better than serum albumin measured alone (PNI, area under the curve 0.679 vs. 0.677, DeLong p = 0.90; HALP, 0.654 vs. 0.677, p = 0.52).

Taken together, the results argue against treating composite laboratory indices as independent markers of geriatric vulnerability: their apparent value largely reflects the albumin and functional components already captured in routine assessment. A low PNI or HALP may still draw attention to a patient who warrants closer functional evaluation, but should not replace direct geriatric assessment.