PSYCHOMETRIC VALIDATION OF THE JAPANESE VERSION OF THE PAIN IMPACT QUESTIONNAIRE (PIQ-6) IN PATIENTS WITH CHRONIC PAIN
Author(s)
Ayumi Morishita, MPH, Kanoko Watanabe, MP, Kazumi Arikawa, BSc, Yuriko Kakiuchi, BA, Shinichiro Ikeda, MD, MBA, Abe Noriyuki, MSc, PhD, Daisuke Kubo, MSc, Kana Tatsukawa, MPH, Sven Demiya, MBA, MSc, PhD, Koki Idehara, PhD.
IQVIA Solutions Japan G.K., Minato-ku, Tokyo, Japan.
IQVIA Solutions Japan G.K., Minato-ku, Tokyo, Japan.
OBJECTIVES: The Pain Impact Questionnaire (PIQ-6) is a 6-item patient-reported outcome measure assessing pain severity and its impact on health-related quality of life. The Japanese version was previously developed following ISPOR task force guidelines for translation and cultural adaptation. This study evaluated the psychometric properties of the Japanese PIQ-6 in patients with chronic pain, including cancer-related pain in Japan.
METHODS: A web-based survey was conducted among Japanese adults with pain conditions. Participants were recruited based on chronic pain conditions defined in the Japanese clinical practice guidelines for chronic pain (2021), including low back pain, knee osteoarthritis, migraine, postherpetic neuralgia, trigeminal neuralgia, and rheumatic diseases, as well as additional conditions consistent with chronic pain, including postoperative and cancer-related pain. Participants who completed the baseline survey, including the PIQ-6 and Numeric Rating Scale (NRS), were invited to complete a retest after two weeks to assess test-retest reliability. Psychometric evaluation included internal consistency (Cronbach’s alpha), test-retest reliability using the intraclass correlation coefficient (ICC), construct validity (correlations with NRS), and structural validity using confirmatory factor analysis (CFA).
RESULTS: A total of 1,896 participants completed the baseline survey, of whom 1,585 (83.6%) completed both assessments. The mean PIQ-6 score was 56.6 (SD: 7.1). Internal consistency was excellent (Cronbach’s alpha: 0.923 overall; 0.908-0.945 across subgroups). Test-retest reliability was good to excellent (ICC: 0.808 overall; 0.714-0.857 across subgroups). Moderate correlations between PIQ-6 and NRS supported construct validity (Spearman’s rho: 0.642 overall; 0.537-0.716 across subgroups). CFA supported a one-factor structure, with slightly lower fit in migraine (RMSEA: 0.143) and postherpetic neuralgia (RMSEA: 0.150).
CONCLUSIONS: The Japanese PIQ-6 demonstrated robust reliability and validity across a wide range of chronic pain conditions, including cancer-related pain and postoperative pain, supporting its use as a standardized and practical measure of pain impact in clinical research and real-world evidence generation in Japan.
METHODS: A web-based survey was conducted among Japanese adults with pain conditions. Participants were recruited based on chronic pain conditions defined in the Japanese clinical practice guidelines for chronic pain (2021), including low back pain, knee osteoarthritis, migraine, postherpetic neuralgia, trigeminal neuralgia, and rheumatic diseases, as well as additional conditions consistent with chronic pain, including postoperative and cancer-related pain. Participants who completed the baseline survey, including the PIQ-6 and Numeric Rating Scale (NRS), were invited to complete a retest after two weeks to assess test-retest reliability. Psychometric evaluation included internal consistency (Cronbach’s alpha), test-retest reliability using the intraclass correlation coefficient (ICC), construct validity (correlations with NRS), and structural validity using confirmatory factor analysis (CFA).
RESULTS: A total of 1,896 participants completed the baseline survey, of whom 1,585 (83.6%) completed both assessments. The mean PIQ-6 score was 56.6 (SD: 7.1). Internal consistency was excellent (Cronbach’s alpha: 0.923 overall; 0.908-0.945 across subgroups). Test-retest reliability was good to excellent (ICC: 0.808 overall; 0.714-0.857 across subgroups). Moderate correlations between PIQ-6 and NRS supported construct validity (Spearman’s rho: 0.642 overall; 0.537-0.716 across subgroups). CFA supported a one-factor structure, with slightly lower fit in migraine (RMSEA: 0.143) and postherpetic neuralgia (RMSEA: 0.150).
CONCLUSIONS: The Japanese PIQ-6 demonstrated robust reliability and validity across a wide range of chronic pain conditions, including cancer-related pain and postoperative pain, supporting its use as a standardized and practical measure of pain impact in clinical research and real-world evidence generation in Japan.
Conference/Value in Health Info
2026-09, ISPOR Asia Pacific 2026, Bangkok, Thailand
Value in Health, Volume 55, Issue S1
Code
PCR22
Topic
Patient-Centered Research
Topic Subcategory
Instrument Development, Validation, & Translation, Patient-reported Outcomes & Quality of Life Outcomes
Disease
SDC: Musculoskeletal Disorders (Arthritis, Bone Disorders, Osteoporosis, Other Musculoskeletal), SDC: Neurological Disorders, SDC: Oncology, SDC: Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)