Lack of Standardized Measurements Clouds Picture of Pain Interventions

Data concerning general outcomes and indicating performance of general pain clinics remain sparse, according to a study in the Journal of Pain and Research. The United Kingdom study suggests that this lack of standardized measurements negatively impacts the ability to judge the overall effectiveness of pain clinics, both in the UK and in other parts of the world.

Although the research concerning chronic pain is vast, the majority of studies have investigated either specific outcomes, such as patient satisfaction with treatment, specific outcomes in specific types of chronic pain, or a range of outcomes in a homogeneous pain population. What’s missing, according to the research, is any kind of standardized outcome reporting, which would be useful not just for patients determining the potential effectiveness of pain treatment, but for health systems overall, and for pain management clinicians in particular.

The study analyzed data from 118 patients with pain at Chelsea and Westminster Hospital, London, UK. The hospital includes a multidisciplinary team comprising pain physicians, physiotherapists, nurse specialists, and clinical psychologists, offering treatment for patients presenting with musculoskeletal or neuropathic pain. The patients were asked to complete the modified short-form Brief Pain Inventory (BPI-SF) during pain follow-up visits.

According to the study authors, “There was considerable variation in impact of pain clinics depending on the outcome measure employed.”

While median pain scores did not differ between admission and follow-up, scores improved individually in 30% of cases, such that more patients had mild pain on follow-up than on admission. Furthermore, while only 41% of patients reported at least moderate subjective improvement after admission to the service, the majority (83%) were satisfied with the service.

“Conflicting data exist as to whether variables routinely assessed in clinics, such as pain scores, quality-of-life indicators, comorbidities, and patient demographics, correlate with or even predict such outcome measures as pain relief or patient satisfaction,” the study authors noted.

The problem, in a nutshell: “If measures of central tendencies (mean or median) were employed to compare pain-intensity ratings on admission to those on follow up, pain clinics seemed not to have an effect at all,” the authors wrote.

But by other measurements, there was a significant impact of pain management care. The variability across all assessed outcomes in the study was very large, possibly not only reflecting the multifaceted nature of pain but also the shortcomings of currently available measurement tools.

Limitations of the study include the possible introduction of bias into the assessment of subjective improvement and patient satisfaction and the disproportionate inclusion of complex cases. The study authors explained that more research is needed to develop instruments that are easily applicable and have high discriminative power.

“Furthermore, to allow appropriate judgments between services in the future, outcome assessments would not only need to be standardized but also would require benchmark comparisons,” the team concluded.