[Onodera prognostic nutrition index predicts nutrition risk in gastrointestinal elective operation patients]

To evaluate the clinical effectiveness of Onodera prognostic nutrition index (OPNI) in the predictive value of nutrition risk.

In a prospective cohort study from July 2014 to June 2015 in the Department of General Surgery of the Ninth People's Hospital of Chongqing, NRS2002 and OPNI were conducted in 200 patients undergoing gastrointestinal elective operation. OPNI was calculated with serum albumin (Alb) and peripheral lymphocyte (TLC) [OPNI=Alb(10(9)/L)+5×TLC(10(9)/L)]. By using the results of NRS2002 as the golden standard for diagnosis of nutrition risk (A NRS2002 score≥3 was deemed as nutritional risk and a nutritional care plan should be initiated. A NRS2002 score <3 was deemed as no nutritional risk), the effectiveness of OPNI was evaluated by the receiver operator characteristic(ROC) curve. The sensitivity, specificity, positive and negative predictive values, Youden indexes and area under ROC curve(AUC) of different diagnostic cut-off points of OPNI were analyzed to determine the optimal operating point (OOP). Kappa test was used to estimate the consistency of different cut-off points for OPNI with NRS2002 in defining nutrition risk.

A total of 103 patients were of NRS2002 ≥3 group, and 97 of NRS2002 <3 group. The overall OPNI was 45.4±7.4. When OOP was 45.8, the AUC of OPNI was 0.914 (95% CI: 0.873 to 0.954); the sensitivity, specificity, Youden indexes were 85.4%, 85.6%, 0.711; the positive predictive value and negative predictive value were 85.3% and 83.7%, respectively. According to this OOP, the subjects were divided into the OPNI ≥45.8 group(n=102) and OPNI <45.8 group (n=98). Compared with OPNI ≥45.8 group, OPNI <45.8 group were older [(66.5±12.1)years vs. (57.0±15.3) years, t=-4.905, P=0.000], and had lower BMI[(20.4±3.0) kg/m(2) vs. (21.7±3.0) kg/m(2), t=3.069, P=0.002], lower albumin[(34.7±4.7)10(9)/L vs.(43.6±3.4)10(9)/L, t=15.542, P=0.000] and lower TLC[(1.0±0.5)10(9)/L vs.(1.6±0.7)10(9)/L, t=7.254, P=0.000], respectively. Kappa test indicated that when using OPNI=45.8, the diagnostic value of OPNI on nutrition risk was consistence with NRS2002(Kappa=0.691, P=0.000).

OPNI can be used as a relatively simple and reliable method for clinical screening and assessment of nutrition risk.