Predictive value of a novel sub-item mortality risk score derived from the Norfolk Quality of Life in Diabetic Neuropathy questionnaire in Romanian participants with diabetes mellitus

Abstract

Aims: To evaluate whether the Norfolk Quality of Life in Diabetic Neuropathy (QOL-DN) questionnaire and the novel Norfolk Mortality Risk Score (NMRS), comprising Norfolk QOL-DN items, can identify 4-year mortality risk in individuals with diabetes.

Methods: Of 21,756 adults completing Norfolk QOL-DN in 2012, two groups of surviving and deceased patients were identified in 2016: Group 1, from a county capital and Group 2, from six small cities. NMRS was calculated in Group 1 using the 2012 scores of Norfolk QOL-DN items that discriminate between deceased and surviving participants (p < 0.05) and was subsequently applied to Group 2.

Results: 763 participants were included (Group 1: 481 [450 surviving, 31 deceased]; Group 2: 282 [218 surviving, 64 deceased]). Total Norfolk QOL-DN score was significantly higher (worse) in deceased participants than in survivors in both groups (p ≤ 0.008). Optimal cut-off for the 25-item NMRS was 11.5 in Group 1. Individuals in Groups 1 and 2 with NMRS≥ 11.5 in 2012 had a 4-year mortality risk ratio of 4.24 (95 % confidence interval [CI]: 1.65-10.84) and 2.33 (95 % CI: 1.33-4.07), respectively, corresponding to 8 and 16 additional deaths/100 persons/4 years (p = 0.001).

Conclusion: Norfolk QOL-DN and NMRS can identify individuals with diabetes at risk of 4-year mortality.

Keywords: Diabetes; Mortality; Quality of life; Questionnaire; Risk.