Minimum clinically important differences in chronic pain vary considerably by baseline pain and methodological factors: systematic review of empirical studies.
Olsen Mette Frahm,Bjerre Eik,Hansen Maria Damkjær,Tendal Britta,Hilden Jørgen,Hróbjartsson Asbjørn
Journal of clinical epidemiology
BACKGROUND:The minimum clinically important difference (MCID) is used to interpret the relevance of treatment effects, e.g., when developing clinical guidelines, evaluating trial results or planning sample sizes. There is currently no agreement on an appropriate MCID in chronic pain and little is known about which contextual factors cause variation. METHODS:This is a systematic review. We searched PubMed, EMBASE, and Cochrane Library. Eligible studies determined MCID for chronic pain based on a one-dimensional pain scale, a patient-reported transition scale of perceived improvement, and either a mean change analysis (mean difference in pain among minimally improved patients) or a threshold analysis (pain reduction associated with best sensitivity and specificity for identifying minimally improved patients). Main results were descriptively summarized due to considerable heterogeneity, which were quantified using meta-analyses and explored using subgroup analyses and metaregression. RESULTS:We included 66 studies (31.254 patients). Median absolute MCID was 23 mm on a 0-100 mm scale (interquartile range [IQR] 12-39) and median relative MCID was 34% (IQR 22-45) among studies using the mean change approach. In both cases, heterogeneity was very high: absolute MCID I = 99% and relative MCID I = 96%. High variation was also seen among studies using the threshold approach: median absolute MCID was 20 mm (IQR 15-30) and relative MCID was 32% (IQR 15-41). Absolute MCID was strongly associated with baseline pain, explaining approximately two-thirds of the variation, and to a lesser degree with the operational definition of minimum pain relief and clinical condition. A total of 15 clinical and methodological factors were assessed as possible causes for variation in MCID. CONCLUSIONS:MCID for chronic pain relief vary considerably. Baseline pain is strongly associated with absolute, but not relative, measures. To a much lesser degree, MCID is also influenced by the operational definition of relevant pain relief and possibly by clinical condition. Explicit and conscientious reflections on the choice of an MCID are required when classifying effect sizes as clinically important or trivial.
10.1016/j.jclinepi.2018.05.007
How Can We Define Clinically Important Improvement in Pain Scores After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? Minimum 2-Year Follow-up Study.
Beck Edward C,Nwachukwu Benedict U,Kunze Kyle N,Chahla Jorge,Nho Shane J
The American journal of sports medicine
BACKGROUND:Patient postoperative pain is being increasingly reported in the field of hip preservation surgery. The visual analog scale (VAS) for pain is one of the most commonly utilized measures for perioperative pain assessment. Currently, there is limited understanding of clinically significant improvement in VAS pain. PURPOSE:(1) To define the substantial clinical benefit (SCB), patient acceptable symptomatic state (PASS), and minimal clinically important difference (MCID) for the VAS pain score in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome after 2 years from surgery and (2) to identify preoperative predictors of achieving each outcome endpoint. STUDY DESIGN:Case series; Level of evidence, 4. METHODS:Data from consecutive patients who underwent primary hip arthroscopy between November 2014 and March 2017 were collected and analyzed. Baseline data and postoperative patient-reported outcome scores were recorded at 2 years postoperatively. To quantify clinical significance of outcome achievement for the VAS pain score, the MCID, PASS, and SCB were calculated. RESULTS:A total of 976 patients were included in the final analysis. The VAS pain score threshold for achieving the MCID was defined as a decrease of 14.8; the PASS was defined as achieving a 2-year postoperative score of 21.6 points; and the SCB was defined as a decrease of 25.5 or a score of 15.4 points at 2 years. The rates of achieving the MCID, PASS, and SCB were 97.6%, 66.4%, and 71.2%, respectively. Regression analysis demonstrated that sports involvement, low body mass index, smaller preoperative alpha angle, and absence of articular damage and chondromalacia were predictive of achieving the PASS (all < .05). Preoperative predictors for achieving the SCB included being male, no smoking history, smaller alpha angle, higher modified Harris Hip Score, and lower VAS pain score (all < .05). CONCLUSION:This study identified scores for VAS pain that can be used to define clinically significant outcome after arthroscopic treatment of femoroacetabular impingement syndrome. Specifically, a decrease in pain score of 14.8 was a clinically important improvement in VAS pain, while an absolute score <15.4 or a change of 25.5 represented the upper threshold of VAS pain improvement. Additionally, there were both modifiable and nonmodifiable factors that predicted achieving clinically significant levels of postoperative pain improvement.
10.1177/0363546519877861
Does the clinically significant difference in visual analog scale pain scores vary with gender, age, or cause of pain?
Kelly A M
Academic emergency medicine : official journal of the Society for Academic Emergency Medicine
OBJECTIVES:To determine the minimum clinically significant difference in visual analog scale (VAS) pain scores for acute pain in the ED setting and to determine whether this difference varies with gender, age, or cause of pain. METHODS:A prospective, descriptive study of 152 adult patients presenting to the ED with acute pain. At presentation and at 20-minute intervals to a maximum of three measurements, patients marked the level of their pain on a 100-mm, nonhatched VAS. At each follow-up they also gave a verbal rating of their pain as "a lot better," "much the same," "a little worse," or "much worse." The minimum clinically significant difference in VAS pain scores was defined as the mean difference between current and preceding scores when pain was reported as a little worse or a little better. Data were compared based on gender, age more than or less than 50 years, and traumatic vs nontraumatic causes of pain. RESULTS:The minimum clinically significant difference in VAS pain scores is 9 mm (95% CI, 6 to 13 mm). There is no statistically significant difference between the minimum clinically significant differences in VAS pain scores based on gender (p=0.172), age (p=0.782), or cause of pain (p=0.84). CONCLUSIONS:The minimum clinically significant difference in VAS pain scores was found to be 9 mm. Differences of less than this amount, even if statistically significant, are unlikely to be of clinical significance. No significant difference in minimum significant VAS scores was found between gender, age, and cause-of-pain groups.
Chiropractic Clinical Outcomes Among Older Adult Male Veterans With Chronic Lower Back Pain: A Retrospective Review of Quality-Assurance Data.
Journal of chiropractic medicine
Objective:The purpose of this study was to determine whether a sample of older adult male U.S. veterans demonstrated clinically and statistically significant improvement in chronic lower back pain on validated outcome measures after a short course of chiropractic care. Methods:We performed a retrospective review of a quality-assurance data set of outcome metrics for male veterans, aged 65 to 89 years, who had chronic low back pain, defined as pain in the lower back region present for at least 3 months before evaluation. We included those who received chiropractic management from January 1, 2010, to December 31, 2018. Paired tests were used to compare outcomes after 4 treatments on both a numeric rating scale (NRS) and the Back Bournemouth Questionnaire (BBQ). The minimum clinically important difference (MCID) was set at 30% change from baseline. Results:There were 217 individuals who met the inclusion criteria. The mean NRS score change from baseline was 2.2 points, representing a 34.1% reduction ( = 13.5, < .001). The mean score change for BBQ was 14.7 points, representing a 35.9% reduction ( = 16.7, < .001). The percentage of participants reaching the MCID for the NRS was 57% (n = 124) and for the BBQ was 59% (n = 126), with 41% (n = 90) of the sample reaching the MCID for both the NRS and BBQ. Conclusion:This retrospective review revealed clinically and statistically significant improvement in NRS and BBQ scores for this sample of older male U.S. veterans treated with chiropractic management for chronic low back pain.
10.1016/j.jcm.2022.02.004
Defining minimal clinically important differences in pain and disability outcomes of patients with chronic pain treated with spinal cord stimulation.
Journal of neurosurgery. Spine
OBJECTIVE:Minimal clinically important difference (MCID) thresholds for a limited number of outcome metrics were previously defined for patients with failed back surgery syndrome (FBSS) at 6 months after spinal cord stimulation (SCS). This study aimed to further define MCID values for pain and disability outcomes. Additionally, the authors established 1-year MCID values for outcome measures with previously defined metrics commonly used to assess SCS efficacy. METHODS:Preoperative and 1-year postoperative outcomes were collected from 114 patients who received SCS therapy for FBSS, complex regional pain syndrome, and neuropathic pain. MCID values were established for the numerical rating scale (NRS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), McGill Pain Questionnaire (MPQ), and Pain Catastrophizing Scale (PCS). Four established anchor-based methods were utilized to compute MCID values with two anchored questions: "Are you satisfied with SCS therapy?" and "Would you have SCS surgery again?" For each question, patients were categorized as responders if they answered "yes" or as nonresponders if they responded "no." The methodologies utilized to compute MCID scores included the average change method, minimum detectable change approach, change difference calculation, and receiver operating characteristic (ROC) analysis. Area under the ROC curve (AUC) analysis has been shown to inform the accuracy at which the MCID value can distinguish responders from nonresponders and was analyzed for each instrument. RESULTS:For the first time, ranges of MCID values after SCS were established for MPQ (1-2.3) and PCS (1.9-13.6). One-year MCID values were defined for all indications: NRS (range 0.9-2.7), ODI (3.5-6.9), and BDI (2-5.9). AUC values were significant for NRS (0.78, p < 0.001), ODI (0.71, p = 0.003), MPQ (0.74, p < 0.001), and PCS (0.77, p < 0.001), indicating notable accuracy for distinguishing satisfied patients. CONCLUSIONS:This was the first study to successfully determine MCID values for two prominent instruments, MPQ and PCS, used to assess pain after SCS surgery. Additionally, previously established MCID values for ODI, BDI, and the visual analog scale for patients with FBSS at 6 months after treatment were explored at 12 months for the most common indications for SCS. These data may better inform physicians of patient response to and success with SCS therapy.
10.3171/2020.11.SPINE201431
The minimum clinically significant difference in patient-assigned numeric scores for pain.
Kendrick Dawn B,Strout Tania D
The American journal of emergency medicine
OBJECTIVE:To determine the minimum clinically significant difference (MCSD) in patient-assigned, 11-point numeric rating scale (NRS-11) scores for pain and to determine if the MCSD varied with demographic characteristics. METHODS:Eligible emergency department patients presenting with pain were asked to rate their pain on the NRS-11 every 20 minutes. Subjects compared pain intensity by choosing from the following verbal descriptor responses: "a lot more," "a little more," "about the same," "a little less," or "a lot less" pain. The MCSD was defined as the difference between scores rated "a little more" or "a little less" severe. RESULTS:Three hundred fifty-four subjects were enrolled. The MCSD was 1.39 +/- 1.05 (95% confidence interval, 1.27-1.51). No statistically significant difference based on sex or pain etiology was noted. CONCLUSIONS:Findings suggest that a change of 1.39 +/- 1.05 (95% confidence interval, 1.27-1.51) on the NRS-11 is clinically significant when measuring pain.
10.1016/j.ajem.2005.07.009
Clinically meaningful differences in pain, disability and quality of life for chronic nonspecific neck pain - a reanalysis of 4 randomized controlled trials of cupping therapy.
Lauche Romy,Langhorst Jost,Dobos Gustav J,Cramer Holger
Complementary therapies in medicine
OBJECTIVES:The assessment of clinically meaningful differences in patients' self-reported outcomes has become increasingly important when interpreting the results of clinical studies. Although these assessments have become quite common there are hardly any data for nonspecific neck pain, especially in the context of complementary and alternative medicine. The aim of this analysis is the determination of minimal clinically important differences (MCID) and substantial clinical benefits (SCB) in patients with chronic nonspecific neck pain after cupping treatment. METHODS:The data set comprised a total of 200 patients with chronic nonspecific neck pain participating in clinical trials on cupping therapy. The MCID and SCB for pain intensity (VAS), neck disability index (NDI) and the subscale bodily pain (SF-36-BP) as well as physical component summary (SF-36-PCS) of the SF-36 were determined using receiver operating characteristic (ROC) curve analysis with an adapted assessment of change in health status (SF-36), i.e. a 5-point Likert scale ranging from "much better" to "much worse", as anchor. MCID derived from the ROC was the score to distinguish "somewhat better" from "about the same", and the SCB was the score to distinguish "much better" from "somewhat better". RESULTS:The calculated MCIDs were: -8mm (-21%) for VAS, -3 points (-10.2%) for NDI, +10 points (+20.5%) for SF-36-BP and +2.6 points (+7.7%) for SF-36-PCS. The SCBs were: -26.5mm (-66.8%) for VAS, -8.4 points (-29%) for NDI, +15.5 points (+43.1%) for SF-36-BP and +5.1 points (+12.9%) for SF-36-PCS. Accuracy of the estimations was good for MCID in general and for SCB regarding VAS and NDI. CONCLUSIONS:The results support the assumption that patients' perceptions of treatment benefits measured by VAS in these trials might be comparable to others in conventional therapies. For NDI and SF-36-PCS the estimated differences were smaller than in previous reports indicating that context factors such as patient characteristics and specific treatment conditions might play an important role. Further studies on MCIDS and SCBs for chronic nonspecific neck pain seem warranted.
10.1016/j.ctim.2013.04.005
Estimating the Minimal Clinically Important Difference on the Visual Analogue Scale for Carpometacarpal Thumb Joint Osteoarthritis.
Hand (New York, N.Y.)
BACKGROUND:The minimal clinically important difference (MCID) is the smallest perceived treatment effect that patients deem clinically significant. There is currently no agreement on an appropriate MCID for the pain visual analogue scale (VAS) in the context of thumb osteoarthritis (OA). METHODS:We approximated MCIDs using a distribution-based approach that pooled standard deviations (SDs) associated with baseline mean values of the pain VAS (0-100 mm). We extracted the data from randomized controlled trials (RCTs) included in a systematic review of adults with long-term OA of the thumb. We excluded RCTs that did not report baseline SD values. The MCIDs were derived at 0.4 and 0.5 SDs of the pooled SD and compared with previously published MCIDs for the pain VAS in OA. RESULTS:A total of 403 patients were pooled from 7 RCTs for the analysis. The mean baseline VAS pain score was 5.6 cm. We derived an MCID of 0.72 cm at 0.4 SDs and 0.91 cm at 0.5 SDs using baseline SDs. We found that MCIDs derived from a distribution-based approach approximated published MCIDs for the VAS for pain for OA in the knee and hip. CONCLUSION:The authors propose that a change of 0.7 to 0.9 cm on the VAS is clinically meaningful in the context of long-term OA of the thumb.
10.1177/15589447241235344
Determining minimal clinically important difference and patient-acceptable symptom state after arthroscopic isolated subscapularis repair.
JSES international
Background:Minimal Clinically Important Difference (MCID) and Patient-Acceptable Symptomatic State (PASS) have emerged as patient-based treatment assessments. However, these have not been investigated in patients undergoing arthroscopic isolated subscapularis repair (AISR). The primary purpose of this study was to determine the MCID and PASS for commonly used patient-reported outcomes in individuals who underwent AISR. The secondary purpose was to assess potential associations between preoperative and intraoperative patient characteristics and the MCID and PASS. Methods:A retrospective analysis was conducted on prospectively collected data for patients who underwent primary AISR between 2011 and 2021 at a single institution, with minimum 2-year postoperative follow-up. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), and Visual Analog Scale (VAS) pain scale. The MCID was determined using the distribution-based method, while PASS was evaluated using area under the curve analysis. To investigate the relationship between preoperative variables and the achievement of MCID and PASS thresholds, Pearson and Spearman coefficient analyses were employed for continuous and noncontinuous variables, respectively. Results:A total of 77 patients with a mean follow-up of 58.1 months were included in the study. The calculated MCID values for VAS pain, ASES, and SSV were 1.2, 10.2, and 13.2, respectively. The PASS values for VAS pain, ASES, and SSV were 2.1, 68.8, and 68, respectively. There was no significant correlation between tear characteristics and the likelihood of achieving a MCID or PASS. Female sex, worker's compensation status, baseline VAS pain score, and baseline ASES score, exhibited weak negative correlations for achieving PASS for VAS pain and ASES. Conclusion:This study defined the MCID and PASS values for commonly used outcome measures at short-term follow-up in patients undergoing AISR. Tear characteristics do not appear to impact the ability to achieve a MCID or PASS after AISR. Female sex, worker's compensation claim, and low baseline functional scores have weak negative correlations with the achievement of PASS for VAS pain and ASES scores.
10.1016/j.jseint.2024.01.014
Minimal Clinically Important Difference and Substantial Clinical Benefit Values for a Pain Visual Analog Scale After Hip Arthroscopy.
Martin RobRoy L,Kivlan Benjamin R,Christoforetti John J,Wolff Andrew B,Nho Shane J,Salvo John P,Ellis Thomas J,Van Thiel Geoff,Matsuda Dean,Carreira Dominic S
Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association
PURPOSE:To define minimal clinically important difference (MCID) and substantial clinical benefit (SCB) values for a pain visual analog scale (VAS) in patients undergoing hip arthroscopy for femoroacetabular impingement or chondrolabral pathology. METHODS:This was a retrospective review of prospective collected data on patients having hip arthroscopy for femoroacetabular impingement and/or chondrolabral pathology. On initial assessment and follow-up between 335 and 395 days postsurgery, subjects completed a pain VAS and categorical self-rating of function. MCID was calculated using one-half the standard deviation (SD) of the change in 1-year pain VAS values. Receiver operator characteristic analysis was performed to determine SCB values. A change in SCB value was determined based on change in categorical self-rating of function to create "improved" and "not improved" groups. Absolute postoperative SCB scores were calculated to determine scores that would be associated with "normal" or "abnormal" function ratings. RESULTS:Of 1,034 eligible patients, 733 (71%) met the inclusion criteria, with 537 (73%) women and 196 (27%) men having a mean age of 35.3 years (SD 13). At a mean of 352 (SD 21) days postsurgery, 536 (73%) were in the improved group and 197 (27%) in the not improved group. MCID was -15.0 mm. A change of -22.7 mm on the pain VAS was able to identify those that improved with high sensitivity (0.74) and specificity (0.63). Values of ≤10.4 mm and ≥29.0 mm were cutoffs identifying subjects that rated their function as normal or abnormal, respectively, with high sensitivity (0.79 and 0.76) and specificity (0.88 and 0.76). CONCLUSIONS:This study provides surgeons with information to help interpret pain VAS values at a follow-up period ranging from 335 to 395 days with MCID and SCB values of -15.0 mm and -22.7 mm, respectively. Additionally, a patient who assesses a pain level at ≤10.4 mm is likely to have a normal rating of function, whereas a patient who assesses a pain level at ≥29.0 mm is likely to have an abnormal rating of function. LEVEL OF EVIDENCE:III, retrospective comparative study.
10.1016/j.arthro.2019.02.032
The minimum clinically significant difference in visual analogue scale pain score does not differ with severity of pain.
Kelly A M
Emergency medicine journal : EMJ
OBJECTIVE:To determine whether minimum clinically significant difference in visual analogue scale (VAS) pain score varies according to the severity of pain reported. METHOD:Prospective descriptive study of adult patients in an urban emergency department (ED). On presentation to the ED, patients marked the level of their pain on a 100 mm, non-hatched VAS scale. At 20 minute intervals thereafter they were asked to give a verbal categorical rating of their pain as "a lot better", "a little better", "much the same", "a little worse" or "much worse" and to mark the level of pain on a VAS scale of the same type as used previously. It was pre-defined that patients with VAS pain scores of 30 mm or less would be categorised as having mild pain, those with scores of 70 mm or more were categorised as having severe pain and those from 31 mm to 69 mm, moderate pain. The minimal clinically significant difference (MCSD) in VAS pain score was defined as the mean difference between current and preceding scores when the subject reported "a little worse" or "a little better" pain. RESULTS:156 patients were enrolled in the study, yielding 88 evaluable comparisons where pain was rated as "a little better" or "a little worse". The MCSD in VAS score in the group overall was 12 mm (95%CI 9 mm to 15 mm). MCSD in VAS score for the "mild pain" group was 11 mm (95%CI 4 mm to 18 mm), for the "moderate pain" group 14 mm (95%CI 10 mm to 18 mm) and for the severe pain group, 10 mm (95%CI 6 mm to 14 mm). There is no statistical difference between the MCSD in VAS score between the severity groups. CONCLUSIONS:The MCSD in VAS pain score does not differ with the severity of pain being experienced.
10.1136/emj.18.3.205
Effects of Myofascial Release in Nonspecific Chronic Low Back Pain: A Randomized Clinical Trial.
Spine
STUDY DESIGN:Double-blind, randomized parallel sham-controlled trial with concealed allocation and intention-to treat analysis. OBJECTIVE:To investigate the effects of an isolate myofascial release (MFR) protocol on pain, disability, and fear-avoidance beliefs in patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA:MFR is a form of manual medicine widely used by physiotherapists in the management of different musculoskeletal pathologies. Up to this moment, no previous studies have reported the effects of an isolated MFR treatment in patients with CLBP. METHODS:Fifty-four participants, with nonspecific CLBP, were randomized to MFR group (n = 27) receiving four sessions of myofascial treatment, each lasting 40 minutes, and to control group (n = 27) receiving a sham MFR. Variables studied were pain measured by means Short Form McGill Pain Questionnaire (SF-MPQ) and visual analog scale (VAS), disability measured with Roland Morris Questionnaire, and fear-avoidance beliefs measured with Fear-Avoidance Beliefs Questionnaire. RESULTS:Subjects receiving MFR displayed significant improvements in pain (SF-MPQ) (mean difference -7.8; 95% confidence interval [CI]: -14.5 to -1.1, P = 0.023) and sensory SF-MPQ subscale (mean difference -6.1; 95% CI: -10.8 to -1.5, P = 0.011) compared to the sham group, but no differences were found in VAS between groups. Disability and the Fear-Avoidance Beliefs Questionnaire score also displayed a significant decrease in the MFR group (P < 0.05) as compared to sham MFR. CONCLUSION:MFR therapy produced a significant improvement in both pain and disability. Because the minimal clinically important differences in pain and disability are, however, included in the 95% CI, we cannot know whether this improvement is clinically relevant. LEVEL OF EVIDENCE:2.
10.1097/BRS.0000000000001897