Chronic Pain Treatment Outcomes Influenced by Nonspecific Factors

Contextual or nonspecific factors may influence treatment outcomes in patients with chronic pain.

Contextual or nonspecific factors may influence treatment outcomes in patients with chronic pain, according to a study presented at the American Pain Society’s 36th Annual Scientific Meeting in Pittsburgh, Pennsylvania.1

Nonspecific factors include a patient’s spirituality and expectations, as well as their trust in a provider’s power to influence treatment outcomes. In clinical trials and research studies, nonspecific factors are rarely taken into account when measuring drug efficacy. Researchers at the University of Pittsburgh, Pennsylvania, therefore developed a list of such factors that might have bearing on healing. They termed this list of patient-reported measures HEAL (Healing Encounters and Attitudes Lists) and developed it based on the PROMIS® methodology, which aims to determine a patient’s “global health” through self-report in 3 PROMIS profile domains: physical health (eg, pain intensity and interference, fatigue, physical function, and sleep disturbance), mental health (eg, anxiety and depression), and social health (eg, participation in social activities).2

The current study sought to assess the predictive value of HEAL delivered by computerized adaptive testing to patients (n=207; average age, 50; 73% women; 73% white) starting treatment for chronic pain (37% back pain; 12% neck pain; 51% neck and back pain) at baseline and after 6 weeks and 16 weeks of treatment. In addition to HEAL, patients completed the Clinical Global Impression of Improvement (CGI) assessment at 6 weeks.3 Study participants were receiving either conventional treatment (n=108) or complementary and alternative medicine treatment (n=99; chiropractic, 36%; physical therapy, 24%; alternative medicines, 11%; massage/bodywork, 7.3%; injections, 7%).

Chronic pain — assessed using the PROMIS pain intensity questionnaire, the Neck Disability Index, and/or the Roland and Morris Back Disability Questionnaire — was reduced at 6 weeks and 16 weeks compared with baseline (P <.001, P =.001, P =.003, respectively). Patients reported improvements on CGI at 6 weeks (feeling “somewhat better,” 50%; “much better,” 20%) and at 16 weeks (“somewhat better,” 47%; “much better,” 25%).

The researchers found the following to predict improvements in PROMIS pain intensity: HEAL Treatment Expectancy, Spirituality, and Attitudes toward complementary and alternative medicine at 6 weeks (17.3% of variance) and HEAL Treatment Expectancy and Spirituality toward conventional medicine at 16 weeks (14.8% of variance). In addition, HEAL patient-provider connection predicted CGI at 16 weeks in patients receiving complementary and alternative medicine (19.1% of variance).

“Nonspecific factors are important to measure, as they influence treatment outcomes. The results from this study show that for both [complementary and alternative medicine] and conventional medicine participants, baseline HEAL Scores predict a portion of outcome variance in pain and global impression of improvement,” conclude the investigators.

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  1. Greco C, Yu L, Dodds N, et al. Nonspecific factors in complementary/alternative medicine (CAM) and conventional treatments: predictive validity of the Healing Encounters and Attitudes Lists (HEAL) in persons with ongoing pain. Presented at: the American Pain Society 36th Annual Scientific Meeting; May 17-20, 2017; Pittsburgh, PA.
  2. Fries JF. New instruments for assessing disability: not quite ready for prime time. Arthritis Rheum. 2004;50(10):3064-3067.
  3. Busner J, Targum SD. The clinical global impressions scale: applying a research tool in clinical practice. Psychiatry (Edgmont). 2007;4(7):28-37.