Psychometric properties of the patient-reported outcomes measurement information system scale v1.2: global health (PROMIS-GH) in a Dutch general population

Purpose To assess the psychometric properties of the Dutch-Flemish Patient-Reported Outcome Measurement Information System Scale v1.2 – Global Health (PROMIS-GH). Methods The PROMIS-GH (also referred to as PROMIS-10) was administered to 4370 persons from the Dutch general population. Unidimensionality (CFI ≥ 0.95; TLI ≥ 0.95; RMSEA ≤ 0.06; SRMR ≤ 0.08), local independence (residual correlations < 0.20), monotonicity (H > 0.30), model fit with the Graded Response Model (GRM, p < 0.001), internal consistency (alpha > 0.75), precision (total score information across the latent trait), measurement invariance (no Differential Item Functioning [DIF]), and cross-cultural validity (no DIF for language, Dutch vs. United States English) of its subscales, composed of four items each, Global Mental Health (GMH) and Global Physical Health (GPH), were assessed. Results Confirmatory factor analyses, on both subscales, revealed slight departures from unidimensionality for GMH (CFI = 0.98; TLI = 0.95, RMSEA = 0.22; SRMR = 0.04) and GPH (CFI = 0.99; TLI = 0.97; RMSEA = 0.12; SRMR = 0.03). Local independence, monotonicity, GRM model fit, internal consistency, precision and cross-cultural validity were supported. However, Global10 (emotional problems) showed misfit on the GMH subscale, while Global08 (fatigue) presented DIF for age. Conclusion The psychometric properties of the PROMIS-GH in the Dutch population were considered acceptable. Sufficient local independence, monotonicity, GRM fit, internal consistency, measurement invariance and cross-cultural validity were found. If future studies find similar results, structural validity of the GMH could be enhanced by improving or replacing Global10 (emotional problems).