Performance of the Angle Labor Pain Questionnaire During Initiation of Epidural Analgesia in Early Active Labor.

BACKGROUND: The Angle Labor Pain Questionnaire (A-LPQ) is a new, 22-item multidimensional psychometric questionnaire that measures the 5 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. Previous work showed that the A-LPQ has overall good psychometric properties and performance during early active labor in women without pain relief. The current study assessed the tool's sensitivity to change during initiation of labor epidural analgesia with the standardized response mean (SRM, primary outcome). METHODS: Two versions of the A-LPQ were administered once, in each of 2 test sessions, by the same trained interviewer during early active labor. The sequence of administration was randomized (ie, standard question order version [Test 1] followed by mixed version [Test 2] or vice versa). Test 1 was completed before epidural insertion; Test 2 commenced 20 to 30 minutes after the test dose. Providers assessed/treated pain independently of the study. Sensitivity to change was assessed using SRMs, Cohen's d, and paired t tests. Overall pain intensity was concurrently examined using Numeric Rating Scale and the Verbal Rating Scale (VRS); coping was assessed with the Pain Mastery Scale. Changes in pain were measured with the Patient Global Impression of Change Scale. Internal consistency was assessed with Cronbach's α. Concurrent validity with other tools was assessed using Spearman's rank correlation coefficient. RESULTS: A total of 51 complete datasets were analyzed. Most women reported moderate (63%, 32/51) or severe (18%, 9/51) baseline pain on VRS scores during Test 1; 29% (15/51) reported mild pain, and 6% (3/51) reported moderate pain during Test 2. Approximately 90% (46/51) of women reported much or very much improved pain at the end of testing. Cronbach's α for A-LPQ summary scores was excellent (0.94) and ranged from 0.78 (acceptable) to 0.92 (excellent) for subscales (Test 1). Large SRMs were found for A-LPQ summary scores (1.6, 95% CI: 1.2, 2.1) and all subscales except the Birthing Pain subscale (moderate, 0.60, 95% CI: 0.23, 0.97). Significant (P < .001) differences were found between A-LPQ summary scores and between all subscales on paired t tests. Correlations between A-LPQ summary and Numeric Rating Scale scores (overall pain intensity) were strong (ρ > 0.73), correlations were moderate (ρ > 0.5) with VRS scores and coping scores (ρ > 0.67). CONCLUSIONS: Findings support A-LPQ use for measurement of women's childbirth pain experiences during initiation of labor epidural analgesia during early active labor. Combined with our previous work, they also support the use of the A-LPQ in late labor and at delivery.

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.