The Angle Labor Pain Questionnaire: Reliability, Validity, Sensitivity to Change, and Responsiveness During Early Active Labor Without Pain Relief.

Objectives: The Angle Labor Pain Questionnaire (A-LPQ) is a new, condition-specific, multidimensional psychometric instrument that measures the most important dimensions of women's childbirth pain experiences using 5 subscales: The Enormity of the Pain, Fear/Anxiety, Uterine Contraction Pain, Birthing Pain, and Back Pain/Long Haul. This study assessed the A-LPQ's test-retest reliability during early active labor without pain relief.

Methods: Two versions of the A-LPQ were randomly administered to laboring women during 2 test sessions separated by a 20-minute window. Participants were of mixed parity, contracting ≥3 minutes apart, cervical dilation ≤6 cm, and without pain relief. Changes in pain were rated using the Patient Global Impression of Change Scale. Overall pain intensity and pain coping were rated using the Numeric Rating Scale (NRS) and the Verbal Rating Scale (VRS) and the Pain Mastery Scale (PMS) respectively. A-LPQ test-retest reliability (primary outcome), Cronbach's α, and concurrent validity with NRS, VRS, and PMS scores were assessed (n=104). Responsiveness was assessed in 55 women who reported changes in pain.

Results: A-LPQ summary and subscale scores demonstrated good test-retest reliability (ICCs, 0.96 to 0.89), trivial to moderate sensitivity to change, and high responsiveness to minimal changes in pain (0.85 to 1.50). Cronbach's α for A-LPQ summary scores was excellent (0.94) and ranged from 0.72 to 0.94 for subscales. Concurrent validity was supported by moderate to strong correlations with NRS and VRS scores for overall pain intensity and PMS scores for pain coping.

Discussion: Findings support A-LPQ use for assessing women's childbirth pain experiences.