Responsiveness and minimal clinically important difference for pain and disability instruments in low back pain patients

Background  

The choice of an evaluative instrument has been hampered by the lack of head-to-head comparisons of responsiveness and the minimal clinically important difference (MCID) in subpopulations of low back pain (LBP). The objective of this study was to concurrently compare responsiveness and MCID for commonly used pain scales and functional instruments in four subpopulations of LBP patients.     

Reporting of minimum clinically important differences in surgical trials

Background: The minimum clinically important difference (MCID) is the smallest difference in outcome between the groups that would be of clinical interest. It influences the estimates that are made to determine the required sample side. The aim of this study was to explore the reporting of the MCID in surgical trials. Method: Surgical trials that were published between January 1981 and December 2006 in five prestigious surgical journals were evaluated. Selected for study were trials that studied two groups and reported the main outcome event as a proportion. Results: Only 21% (100/486) of the admissible surgical trials mentioned a value for the MCID when estimating the sample size. There was a trend, however, for compliance with these factors to increase during the study period. The present post‐hoc calculations of the required sample size, which were based on the observed differences between the groups at the end of the study, suggested that one‐third of the trials should have accrued at least fivefold the number of patients. Although reporting an estimate of the sample size was associated with the study of more patients (median sample size 145 vs 100), it was not associated with the reporting of more positive results, that is, 61% (95/155) versus 65% (214/331). Conclusion: There has been an improvement in the proportion of surgical trials reporting formal estimates of sample size during the last three decades. But the construct of these estimates is often suspect because of a failure to provide realistic values for the MCID.     

Significant differences of brain blood flow in patients with chronic low back pain and acute low back pain detected by brain SPECT

Background

The aim of this study was to examine and compare the areas of brain blood flow in patients with chronic low back pain (CLBP) without structural abnormality and acute low back pain (ALBP) with lumber disc herniation (LDH). Functional neuroimaging studies provide evidence of abnormalities in the regional cerebral blood flow during low back pain. Recent studies have shown that CLBP is associated with plastic, pathophysiological changes in the brain. However, there has been no report yet statistically or by neuro-images on the compared brain single photon-emission computed tomography (SPECT) findings between CLBP and ALBP patients.

Methods

The subjects comprised 14 patients, 7 CLBP and 7 ALBP patients. The CLBP group included the patients who had no or minor structural abnormality in the lumbar spine on magnetic resonance imaging (MRI) and met the criteria for a classification of “pain disorder” (chronic) according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision. The ALBP group included the patients who had symptoms within 3 months of onset and LDH revealed by MRI. All patients were assessed using brain SPECT. We then performed a two-tailed view analysis using the easy Z score imaging system, determined the mean Z scores, and performed vBSEE software (Fujifilm RI Pharma, Tokyo, Japan) for both CLBP and ALBP patients.

Results

The CLBP group showed significantly reduced blood flow in the bilateral prefrontal cortex of the frontal lobe and increased blood flow in the bilateral posterior lobe of the cerebellum.

Conclusions

SPECT images and statistical analyses revealed the brain blood flow alterations in the patients with ALBP and CLBP. These results may suggest that the dysfunction of the prefrontal cortex could lead to the appearance of unconscious pain behavior controlled by the cerebellum in the patients with CLBP.     

Danish version of the Oswestry disability index for patients with low back pain. Part 2: Sensitivity, specificity and clinically significant improvement in two low back pain populations

In studies evaluating the efficacy of clinical interventions, it is of paramount importance that the functional outcome measures are responsive to clinically relevant change. Knowledge thereof is in fact essential for the choice of instrument in clinical trials and for clinical decision-making. This article endeavours to investigate the sensitivity, specificity and clinically significant improvement (responsiveness) of the Danish version of the Oswestry disability index (ODI) in two back pain populations. Two hundred and thirty three patients with low back pain (LBP) and/or leg pain completed a questionnaire booklet at baseline and 8 weeks follow-up. Half of the patients were seen in the primary (PrS) and half in the secondary sectors (SeS) of the Danish Health Care System. The booklet contained the Danish version of the ODI, along with the Roland Morris Questionnaire, the LBP Rating Scale, the SF36 (physical function and bodily pain scales) and a global pain rating. At follow-up, a 7-point transition question (TQ) of patient perceived change and a numeric rating scale relating to the importance of the change were included. Responsiveness was operationalised using three strategies: change scores, standardised response means (SRM) and receiver operating characteristic (ROC) analyses. All methods revealed acceptable responsiveness of the ODI in the two patient populations which was comparable to the external instruments. SRM of the ODI change scores at 2 months follow-up was 1.0 for PrS patients and 0.3 for SeS (raw and percentage). A minimum clinically important change (MCID) from baseline score was established at 9 points (71%) for PrS patients and 8 points (27%) for SeS patients using ROC analyses. This was dependable on the baseline entry score with the MCID increasing with 5 points for every 10 points increase in the baseline score. We conclude that the Danish version of the ODI has comparable responsiveness to other commonly used functional status measures and is appropriate for use in low back pain patients receiving conservative care in both the primary and secondary sector.     

Assessment of sexual activity in patients with back pain compared with patients with neck pain

Recent research has shown significant adverse effects of chronic low back pain on sexual activity in 46% of patients. To establish whether and how chronic low back pain adversely affects sexual activity, a questionnaire-based study was conducted on a patient group (low back pain) and a comparison group (neck pain). Patients were administered a visual analog scale, a series of conventional questionnaires, and a specifically designed sexual activity questionnaire covering frequency of intercourse before and since onset of pain, discomfort during intercourse, satisfaction with sexual life, and comfortable and uncomfortable basic coital positions. Patients with low back pain reported more interference than did patients with neck pain, and women with low back pain were more affected than men. Compared with the other groups, women with low back pain had greater reduction in frequency of intercourse, more marked discomfort during intercourse, and more interference with their sexual lives. The most pain generating position was prone for both genders, and the most comfortable one was supine. Sexual impairment, more marked in women, seems to be related to the triggering of pain by intercourse and to psychologic factors.     

汉译Roland-Morris功能障碍调查表评估下腰痛患者的可靠性

目的:探讨应用汉译Roland-Morris功能障碍调查表评定下腰痛患者的可靠性。方法:将Roland-Morris功能障碍调查表按一定的要求翻译成中文调查表(CRMDQ),对48例住院拟手术的下腰痛患者(男30例,女18例;年龄26～73岁,平均38.5岁),用CRMDQ、中文版Oswestry功能障碍指数(CODI)、视觉模拟评分(VAS)先后进行两次测试,间隔期2d,检测CRMDQ的可重复性;对门诊158例下腰痛患者在就诊时行CRMDQ、CODI、VAS测试,对CRMDQ与CODI、VAS测试结果进行Spearman秩相关分析。结果:CRMDQ具有良好的可重复性(r=0.945,P<0.01);在CRMDQ有效性测试中,与CODI、VAS比较显示出显著的相关性(CRMDQ-CODI:r=0.386;CRMDQ-VAS:r=0.478,P<0.05)。结论:CRMDQ测试具有良好的可重复性和有效性,可用于对下腰痛患者的功能障碍评估。     

椎间盘源性腰痛患者PI-NRS评分与血清6-keto-PGF1α水平的相关性研究

目的观察椎间盘源性腰痛患者血清6-keto—PGF1α水平，探讨临床PI—NRS（11点疼痛数字量表）评分值与其的关系。方法A组（试验组）椎间盘源性腰痛患者20例，B组（对照组）同期健康献血者10例，根据PI-NRS评分值将A组分为A1（n=6，NRS值0—3）、A2（n=10，NRS值4—6）、A，（n=4，NRS值7—10）3组，检测血清6=keto—PGF1d。结果血清6-keto—PGF1α测定结果：A组〉B组，差异具有统计学意义（P〈0．05）；在A1、A2、A3组血液中6-keto—PGF1α含量水平随PI—NRS评分值的增高而增高。结论临床PI-NRS评分与血清6-keto—PGF1α水平具有统计学相关性，PI—NRS值可以反映椎间盘周围组织炎症反应程度。     

Preoperative patient activation predicts minimum clinically important difference for PROMIS pain and physical function in patients undergoing elective spine surgery

BACKGROUND CONTEXTPatient activation is a patient's willingness to take independent actions to manage their own health care.PURPOSEThe goal of this study is to determine whether preoperative patient activation measure (PAM) predicts minimum clinically important difference (MCID) for Patient-Reported Outcomes Measurement Information System (PROMIS) pain, physical function, depression, and anxiety for patients undergoing elective spine surgery.STUDY DESIGN/SETTINGRetrospective review.PATIENT SAMPLEA single-institution, academic database of patients undergoing elective spine surgery.OUTCOME MEASUREMCID at 1-year follow-up for PROMIS pain, physical function, depression and anxiety.METHODSWe retrospectively reviewed a single-institution, academic database of patients undergoing elective spine surgery. Preoperative patient activation was evaluated using the PAM-13 survey, which was used to stratify patients into four activation stages. Primary outcome variable was achieving MCID at 1-year follow-up for PROMIS pain and physical function. Multivariable logistic regression analysis was used to determine impact of patient activation on PROMIS pain and the physical function.RESULTSOf the 430 patients, 220 (51%) were female with a mean age of 58.2±16.8. Preoperatively, 34 (8%) were in activation stage 1, 45 (10%) in stage 2, 98 (23%) in stage 3, and 253 (59%) in stage 4. At 1-year follow up, 248 (58%) achieved MCID for PROMIS physical function, 256 (60%) achieved MCID for PROMIS pain, 151 (35.28%) achieved MCID for PROMIS depression, and 197 (46%) achieved MCID for PROMIS anxiety. For PROMIS physical function, when compared to patients at stage 1 activation, patients at stage 2 (aOR:3.49, 95% CI:1.27, 9.59), stage 3 (aOR:3.54, 95% CI:1.40, 8.98) and stage 4 (aOR:7.88, 95% CI:3.29, 18.9) were more likely to achieve MCID. For PROMIS pain, when compared against patients at stage 1, patients at stage 3 (aOR:2.82, 95% CI:1.18, 6.76) and stage 4 (aOR:5.44, 95% CI:2.41, 12.3) were more likely to achieve MCID. For PROMIS depression, when compared against patients at stage 1, patients at stage 4 were more likely to achieve MCID (Adjusted Odds Ratio (aOR):2.59, 95% CI:1.08–6.19). For PROMIS anxiety, when compared against patients at stage 1, stage 3 (Adjusted Odds Ratio (aOR):3.21, 95% CI:1.20–8.57), and stage 4 (aOR:5.56, 95% CI:2.20–14.01) were more likely to achieve MCID.CONCLUSIONPatients at higher stages of activation were more likely to achieve MCID for PROMIS pain, physical function, depression, and anxiety at 1-year follow-up. Routine preoperative assessment of patient activation may help identify patients at risk of poor outcomes.