Age differences in postoperative pain are scale dependent: a comparison of measures of pain intensity and quality in younger and older surgical patients

Abstract

As the population ages, research into the assessment of postoperative pain in older patients is urgently needed. The reliability and validity of most pain scales for the assessment of acute postoperative pain in the elderly remain to be demonstrated. The present study reports the analysis of age-related patterns on three pain scales (McGill Pain Questionnaire, MPQ; Present Pain Intensity, PPI; and Visual Analog Scale, VAS) completed by younger (n:95, mean age:56.4r-5.8 years) and older (n:105; mean age:66.8 +2.7 years) men following radical prostatectomy. All patients received intravenous morphine via patient-controlled analgesia (PCA) throughout the study. On the first 2 postoperative days (POD), patients completed the pain scales and PCA opioid intake was recorded. An interaction was found between amount of opioid self-administered and POD. In both groups, less opioid was administered on POD 2 than POD 1, but the decrease over time was greater in younger than older men. On both PODs, older men self-administered less opioid than younger men. Age differences in pain were dependent on the pain scale used. Older men had significantly lower scores than younger men on the MPQ and PPI but there were no differences on the VAS. Several age differences in the psychometric properties of the scales were evident. On both PODs, the correlation between VAS and MPQ scores was significantly lower in the older than younger group. POD effect sizes did not differ between the scales or age groups suggesting that all three scales have comparable sensitivity within an age group. However, the different results between the scales for the effect of age suggests that the VAS is not sufficiently sensitive to detect age differences. Therefore, age differences in postoperative pain are better captured by verbal descriptions of pain qualities than non-verbal measures of intensity.

Psychometric properties of pain intensity scales comparing among postoperative adult patients, elderly patients without and with mild cognitive impairment in China

“…However, the present findings are also contrary to the previous study (Gagliese & Katz, 2003) reporting that age differences in the convergent validity were evident since the correlation between the VAS and the McGill Pain Questionnaire (MPQ) scores was significantly lower in the old adult group than young adult group. This discrepancy might be explained by the methodological differences in evaluating convergent validity between Gagliese and Katz's study and the present study.…”

“…For one thing, the findings of age differences in the psychometric properties of the pain scales are inconsistent. Some studies found that age differences in the psychometric properties of the pain scales were evident (Gagliese & Katz, 2003;Peters et al, 2007). However, another study failed to find the age differences in the psychometric properties of the pain scales (Li et al, 2007).…”

“…Pain assessment in older adults may be difficult because of the physiologic, psychosocial, and cognitive changes which accompany ageing (Brunner & Suddarth, 2000). One study found that elderly patients self-administered less opioids than younger patients in the first two postoperative days (Gagliese & Katz, 2003). In addition, the elderly might be more reluctant to report painful stimuli than younger people because the elderly adopted a more conservative response bias when experiencing noxious stimuli (Gagliese & Melzack, 2006).…”

Safety of opioid patch initiation in Australian residential aged care

“…Older patients, matched for surgical procedure, reported less pain in the postoperative period: pain intensity decreased by 10% to 20% each decade after 60 years of age Level III-2). Older men undergoing prostatectomy reported less pain on a present pain intensity scale and McGill Pain Questionnaire (but not a visual analogue scale [VAS]) in the immediate postoperative period and used less PCA opioid than younger men undergoing the same procedure (Gagliese & Katz, 2003 Level III-2). In a study of pain following placement of an IV cannula (a relatively standardised pain stimulus), older patients reported significantly less pain than younger patients (Li et al, 2001 Level IV).…”

Commentary on Tse MMY, Pun SPY & Benzie IFF (2005) Pain relief strategies used by the older people with chronic pain: an exploratory survey for planning patient‐centred intervention. Journal of Clinical Nursing 14, 315–320

“…In some practice settings, the experiences of older and younger people have been compared to examine pain and analgesic administration and all of the research found no difference in pain intensity between the groups. However, analgesic consumption has been significantly lower in older age groups (Oberle et al 1990, Feldt et al 1998, Celia 2000, Gagliese et al 2000, Gagliese & Katz 2003. Health care professionals administering more analgesics to younger people, older people under-reporting pain and increased sensitivity to opioid analgesia in older people have all been offered as explanations.…”