Global Pain State Questionnaire: Reliability, Validity, and Gender Gap

Author(s): Jordi Barrachina, Javier Muriel, Cesar Margarit, Beatriz Planelles, Pura Ballester, Miguel Richart-Martínez, Esperanza Cutillas, Thomas Zandonai, Domingo Morales, Ana M Peiró

Objective: To quantify patients’ pain more objectively is essential to guide an individualized therapy, all the more so in patients under long-term opioid-use. Only a thoughtful and objective understanding of risks and benefits could improve an individualized standard of care. Our aim was to assess metric reliability and validity of an integrated and self-report Global Pain Status questionnaire to quantify the impact of pain on patient’s health in a more precise manner.

Methods: A cross-sectional study was conducted to analyse the reliability, agreement, and validity of an integrated questionnaire compared to isolated scales, due to kappa statistics, intra- class and other correlation coefficients. Level of pain (intensity and relief), quality of life, most prevalent analgesic adverse events and hospital frequentation were registered in a total of 38 cases (pain unit patients) and 52 painless matched-controls.. A reduced multitrait-multimethod matrix and a canonical-correlation analysis were developed together with a multiple linear regression.

Results: Cases (56 ± 10 years old, 63% females, pain intensity 66 ± 23 mm, incidence rate of 5 adverse events) represented a regular pain population. A high intraobserver correlation (r0.75- 0.88, weighted-κ 0.41–0.51, unweighted-κ 0.66-0.82) was evidenced together with significant correlation coefficients in test-retest reliability, and for validity, even more, in a reduced multitrait-multimethod matrix (>0.8) and canonical-correlation (>0.95). A gender gap was evidenced in cases’ companions, mostly middle-aged females (78%), who experienced negative effects on their health.

Conclusions: The Global Pain Status questionnaire is an evaluation instrume