Sensitivity of Single-domain Versus Multiple-domain Outcome Measures to Identify Responders in Chronic Low-back Pain: Pooled Analysis of 2 Placebo-controlled Trials of Etoricoxib

Focused Evidence Review: Psychometric Properties of Patient-Reported Outcome Measures for Chronic Musculoskeletal Pain

BACKGROUND

Developing successful interventions for chronic musculoskeletal pain requires valid, responsive, and reliable outcome measures. The Minneapolis VA Evidence-based Synthesis Program completed a focused evidence review on key psychometric properties of 17 self-report measures of pain severity and pain-related functional impairment suitable for clinical research on chronic musculoskeletal pain.

METHODS

Pain experts of the VA Pain Measurement Outcomes Workgroup identified 17 pain measures to undergo systematic review. In addition to a MEDLINE search on these 17 measures (1/2000-1/2017), we hand-searched (without publication date limits) the reference lists of all included studies, prior systematic reviews, and-when available-Web sites dedicated to each measure (PROSPERO registration CRD42017056610). Our primary outcome was the measure's minimal important difference (MID). Secondary outcomes included responsiveness, validity, and test-retest reliability. Outcomes were synthesized through evidence mapping and qualitative comparison.

RESULTS

Of 1635 abstracts identified, 331 articles underwent full-text review, and 43 met inclusion criteria. Five measures (Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RMDQ), SF-36 Bodily Pain Scale (SF-36 BPS), Numeric Rating Scale (NRS), and Visual Analog Scale (VAS)) had data reported on MID, responsiveness, validity, and test-retest reliability. Seven measures had data reported on three of the four psychometric outcomes. Eight measures had reported MIDs, though estimation methods differed substantially and often were not clinically anchored.

CONCLUSIONS

In this focused evidence review, the most evidence on key psychometric properties in chronic musculoskeletal pain populations was found for the ODI, RMDQ, SF-36 BPS, NRS, and VAS. Key limitations in the field include substantial variation in methods of estimating psychometric properties, defining chronic musculoskeletal pain, and reporting patient demographics.

TRIAL REGISTRATION

Registered in the PROSPERO database: CRD42017056610.

Power of treatment success definitions when the Canine Brief Pain Inventory is used to evaluate carprofen treatment for the control of pain and inflammation in dogs with osteoarthritis

OBJECTIVE

To determine the optimal method for use of the Canine Brief Pain Inventory (CBPI) to quantitate responses of dogs with osteoarthritis to treatment with carprofen or placebo.

ANIMALS

150 dogs with osteoarthritis.

PROCEDURES

Data were analyzed from 2 studies with identical protocols in which owner-completed CBPIs were used. Treatment for each dog was classified as a success or failure by comparing the pain severity score (PSS) and pain interference score (PIS) on day 0 (baseline) with those on day 14. Treatment success or failure was defined on the basis of various combinations of reduction in the 2 scores when inclusion criteria were set as a PSS and PIS ≥ 1, 2, or 3 at baseline. Statistical analyses were performed to select the definition of treatment success that had the greatest statistical power to detect differences between carprofen and placebo treatments.

RESULTS

Defining treatment success as a reduction of ≥ 1 in PSS and ≥ 2 in PIS in each dog had consistently robust power. Power was 62.8% in the population that included only dogs with baseline scores ≥ 2 and 64.7% in the population that included only dogs with baseline scores ≥ 3.

CONCLUSIONS AND CLINICAL RELEVANCE

The CBPI had robust statistical power to evaluate the treatment effect of carprofen in dogs with osteoarthritis when protocol success criteria were predefined as a reduction ≥ 1 in PIS and ≥ 2 in PSS. Results indicated the CBPI can be used as an outcome measure in clinical trials to evaluate new pain treatments when it is desirable to evaluate success in individual dogs rather than overall mean or median scores in a test population.

Genetic variations in interleukin-8 and interleukin-10 are associated with pain, depressed mood, and fatigue in lung cancer patients

CONTEXT

A report by the National Cancer Institute identified that an important gap in symptom research is the investigation of multiple symptoms of cancer that might identify common biological mechanisms among cancer-related symptoms.

OBJECTIVES

We applied novel statistical methods to assess whether variants of 37 inflammation genes may serve as biologic markers of risk for severe pain, depressed mood, and fatigue in non-Hispanic white patients with non-small cell lung cancer.

METHODS

Pain, fatigue, and depressed mood were assessed before cancer treatment. We used a generalized, multivariate, classification tree approach to explore the influence of single-nucleotide polymorphisms in the inflammation genes in pain, depressed mood, and fatigue in lung cancer patients.

RESULTS

Among patients with advanced-stage disease, interleukin (IL)-8-T251A was the most relevant genetic factor for pain (odds ratio [OR] = 2.18, 95% CI = 1.34-3.55, P = 0.001), depressed mood (OR = 0.37, 95% CI = 0.14-1.0), and fatigue (OR = 2.07, 95% CI = 1.16-3.70). Among those with early-stage non-small cell lung cancer, variants in the IL-10 receptor were relevant for fatigue among women. Specifically, women with Lys_Glu or Glu_Glu genotype in the IL-10 gene had a 0.49 times lower risk of severe fatigue compared with those with Lys_Lys genotype (OR = 0.49, 95% CI = 0.25-0.92, P = 0.027). Among men with early-stage lung cancer, a marginal significance was observed for IL-1A C-889T, C/T, or T/T genotypes. These men had a lower risk of severe fatigue compared with those with C/C genotype (OR = 0.38, 95% CI = 0.13-1.06).

CONCLUSION

The interaction of multiple inflammation genes, along with nongenetic factors, underlies the occurrence of symptoms. IL-8 and IL-10 may serve as potential targets for treating multiple symptoms of cancer.