Applicability Research Of Pain Measurement Tools’ Response Patterns In Patients With Chronic Low Back Pain

ObjectiveWe aim to evaluate the preference of patients with low back pain on response patterns of pain measurement instruments, and to investigate these instruments applicability among Chinese population. To explore the applicability and the evaluation characteristic of Short Form-Health Scale of Traditional Chinese Medicine （SF-HSTMC） in patients with chronic low back pain is the second purpose of our study.MethodA total of 444 patients with chronic low back pain were recruited from the outpatient Departments of Orthopaedic, Massage, Acupuncture, Physiotherapy of the Guangdong Provincial Hospital of Chinese Medicine. We explored the preference of response patterns for a number of pain measurement instruments, and the applicability evaluation of these instruments. The instruments included horizontal visual analog scale （H-VAS）, vertical visual analogue scale （V-VAS）, Numeric rating scale （NRS）, Verbal rating Intensity scale, （VPIS）, Wong-baker FACES pain rating scale （FACES scale）.We used the Roland-Morris Disability Questionnaire （RMDQ） as reference tool for analyses. SF-HSTCM was adopted to assess health status of patients with low back pain, and the evaluation characteristic of SF-HSTCM among these patients was also explored. We used descriptive analysis to describe the response patterns of pain measurement instruments and applied correlation analysis to evaluate the reliability between these tools and RMDQ. We used Cronbach’s alpha coefficient to assess the internal consistency reliability and Split-half reliability of SF-HSTCM. We adopted confirmatory factor analysis to detect validity of SF-HSTCM.ResultThere were 98.7% patients responded by returning back the questionnaire.Respponse rate for various response patterns of pain measurement tools, SF-HSTCM and RMDQ were 97.8%,97%,97.6% respectively. The average score of H-VAS, V-VAS, NRS, SF-HSTCM and RMDQ were as follows （X±SD）:51.12±21.75, 48₅0±22. 56,5. 24±2.06,61.74±14.39 and 8. 96土5. 09. Pearson correlation coefficient between H-VAS, V-VAS, NRS and RMDQ was 0.416,0.426 and 0.418 respectively. Spearman correlation coefficient between VPIS, FACES scale and RMDQ was 0.382 and 0. 340. Frequencies of number of patients who chose the pain measurement tool as their preferences were FACES scale（n = 216）,NRS（n = 108）,VPIS（ n = 89）,H-VAS（n = 15）,V-VAS（n = 6）. The cumulative frequencies of their preferences in top 2 was FACES scale（n = 292）, NRS（n = 255）, VPIS（ n=228）,H-VAS（n = 64）, V-VAS（n = 29） : in the top 3 was VPIS（ n = 369）,NRS（n=367）,FACES scale（n = 351）, H-VAS（n = 140）:Vertical visual analog scale（n=75）. Among 75 kinds of permutation and combination the ones chosen by more than 10 patients were dacbe（n=61）,dcabe（n二51）,cdabe（n=25）,acdbe（n=23）,adcbe（n=19）、cadbe（n=17）,dcaeb（n=17）,daceb（n=16）,abcde（n=10）,adced（n=10）(while a, b, c, d, e represented NRS, H-VAS, VPIS, FACES scale and V-VAS. Cronbach’ s alpha coefficient of SF-HSTCM for the internal consistency reliability was 0. 914.Cronbach’s alpha coefficient of SF-HSTCM for Split-half reliability was0.763. Each dimension of SF-HSTCM internal consistency : Cronbach ’s alpha coefficient of Adaptability of Social Environment（tASE） was 0.886. Cronbach’s alpha coefficient of Physical Functioning under Natural Environment（tPFNE）was 0. 826. Cronbach ’ s alpha coefficient of Spirit（tSP） was 0. 795. Cronbach’ s alpha coefficient of Ability of contacting with People（tACP） was 0.733. the Cronbach,s alpha coefficient of Adaptability of Natural Environment（tANE） was0. 625. Testing of the goodness of fit between between the scale structure and the obtained data from this population showed that RMSEA was 0.062, NNFI was0. 96 and GFI 0.88,CFI 0. 96.ConclusionIn patients with chronic low back pain in China, response pattern used in FACES scale was the most easily accepted one among all five scales, i. e. FACES scale, NRS, V-VAS, H-VAS,VPIS. FACES scale, NRS, VPIS is relatively more applicable in patients with low back pain in China. SF-HSTCM shows good reliability when it is adopted in these patients, but the goodness of fit is general. The response patterns of pain measurement tools in Chinese populationare valuable for further researches.