Conference Coverage

Study finds inaccurate reporting of pain by back pain sufferers




SAN DIEGO – Patients with chronic low back pain who report pain scores that do not correlate well with their functional activity level are less satisfied with their pain management treatment, a single-center study found.

“Taking into account that the Affordable Healthcare Act is planning to base physician reimbursements on patient satisfaction with provided treatment, it is imperative to educate patients regarding the necessity to accurately report their pain level using a numeric rating scale. We must also identify other parameters in defining our patients’ chronic pain conditions, such a functionality scales and quality of life questionnaires,” Dr. Nebojsa Nick Knezevic said at the annual meeting of the American Society of Anesthesiologists.

Dr. Nebojsa N. Knezevic

Dr. Nebojsa N. Knezevic

“We rely on many different types of scales for pain, including Likert scales, visual analog scales, and numerical pain rating scales,” said Dr. Knezevic, vice chair for research and education at Advocate Illinois Masonic Medical Center, Chicago. “However, there are many reports talking about the subjectivity of these scales. Interpretation of the pain scores can underestimate or overestimate patient conditions, and they may go on to receive treatments that are not indicated.”

In an effort to assess how numeric pain scores reported by patients with chronic low back pain correlate with their functional activity levels and satisfaction with their pain management, Dr. Knezevic and his associates enrolled 100 patients with radicular low back pain and a mean age of 49 years. Overall, 56% were female, and their average duration of low back pain prior to study enrollment was 14 months.

The investigators asked them to complete pain scores on an 11-point numeric rating scale at rest and during movement, as well as the Oswestry Disability Index (ODI) questionnaire. The researchers evaluated the patients 10 times over a 1-year period at the same time points and asked them to grade their satisfaction with pain management on a scale from 1 to 5, where 1 meant completely dissatisfied, 2 meant dissatisfied, 3 meant somewhat satisfied, 4 meant satisfied, and 5 meant completely satisfied. The investigators multiplied the pain scores by 10 to be on the same 0-100 scale as the ODI and compared the values at each visit. Differences between the ODI and pain scores in the range of –10% to +10% were considered normal, while differences between 11% and 30% were considered mild, differences between 31% and 50% were considered moderate, and differences of more than 50% were considered severe.

Dr. Knezevic reported that pain scores at rest correlated well with ODI in 65% of patients, while mild discrepancies were present in 30% of patients, moderate discrepancies in 4%, and severe discrepancies in 1%. On the other hand, pain scores during movement correlated well with ODI in only 39% of patients, while mild discrepancies were present in 42% of patients, moderate discrepancies in 14%, and severe discrepancies in 5%. More than half of patients (58%) reported pain levels during movement that did not correlate with the level of functional activity indicated by their ODI score. However, inconsistencies between male and female pain score reporting at rest and during movement were equal (P = .606 and P = .928, respectively).

The researchers also found that patients who were taking opioids showed greater discrepancy in reporting pain intensity scores, compared with patients using nonopioid analgesics, as well as those who were not taking medications for their low back pain (P = .038).

“Results of this study showed negative correlation between the degree of discrepancy in pain scores and patient satisfaction with pain management treatment,” Dr. Knezevic concluded.

Dr. Knezevic reported having no financial disclosures.

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