Numerical rating scale for dysmenorrhea-related pain: a clinimetric study

Abstract

Objective: To evaluate the numerical rating scale (NRS) measurement properties in women with dysmenorrhea. Methods: This was an online clinimetric study. Brazilian women aged over 18 years old with internet access to respond to online instruments were included in the study. We evaluated criterion validity (comparing women with and without dysmenorrhea), construct validity between the NRS and the bodily pain domain of the SF-36, test-retest reliability, and measurement errors (in women with dysmenorrhea). Results: Two hundred thirty-eight women with and 192 without dysmenorrhea participated in the study. For criterion validity, the area under the receiver operating characteristic curve was 0.902 (95%CI, 0.873–0.931), and a cutoff point of 3 was considered to have the best sensitivity (83%) and specificity (86%). For construct validity, the NRS showed a moderate negative correlation with the SF-36 bodily pain domain (r=-0.46; p < 0.001). For test-retest reliability and measurement errors, 105 women whose symptoms did not change between 7 and 10 days of retest, with intraclass correlation coefficient = 0.90, standard error of measurement = 0.97, and smallest detectable change = 2.76 points. Conclusions: The NRS can be considered a valid and reliable patient-reported outcome measure for assessing dysmenorrhea-related pain intensity.

摘要

目的

评估痛经女性应用数字评定量表 (NRs)的测量特性。

方法

这是一项在线的临床研究。该研究纳入年龄超过 18 岁、可以使用互联网应用在线工具的巴西女性。我们评估了效标效度（比较有和无痛经的女性）、NRs 和 sF-36量表躯体疼痛部分的建构效度、重测信度和测量误差（有痛经的女性）。

结果

238 名有痛经和 192 名无痛经的女性参加了本项研究。对于标准效度, 接受者操作特性曲线（ROC曲线）下面积为 0.902（95%ci, 0.873-0.931）, 以3为截断值具有最佳灵敏度（83%）和特异性（86%）。NR 与 sF-36 的躯体疼痛部分的建构效度呈中度负相关（r=-0.46；p<0.001）。对于重测信度和测量误差, 105 名女性的症状在7-10天之间重测无变化, 组内相关系数 = 0.90, 测量标准误差 = 0.97, 最小可检测变化=2.76分。

结论

可认为NRs是评估患者报告痛经相关疼痛强度的有效和可靠的测试结果。

Keywords:

• Dysmenorrhea
• women’s health
• chronic pain
• validation study
• measurement properties

关键词:

• 痛经
• 女性健康
• 慢性疼痛
• 验证研究
• 测量特性

Acknowledgements

We thank the participants for their contribution to the study.

Conflicts of interest and source of funding

The authors declare no conflict of interest.

Data availability

Data from the present study will be made available at reasonable request.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was partially financed by Coordination for Improvement of Higher Education Personnel (CAPES), Brazil, Finance Code 001 and by São Paulo Research Foundation (process 2019/14672-7). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.