Psychometric Evaluation of Selected Pain Intensity Scales for Use with Cognitively Impaired and Cognitively Intact Older Adults

Abstract

The purpose of this study was to determine the reliability and validity of selected pain intensity scales such as the Faces Pain Scale (FPS), the Verbal Descriptor Scale (VDS), the Numeric Rating Scale (NRS), and the Iowa Pain Thermometer (IPT) to assess pain in cognitively impaired older adults. A descriptive correlational design was used, and a convenience sample of 66 volunteers age 60 and older residing in assisted living facilities in the South was recruited for this study. The sample included 22 (33%) men and 44 (67%) women, with a mean age of 76. Ninety-eight percent (65) of the sample comprised Caucasian participants, with the exception of 1 African-American man. Seventy percent (47) completed high school and/or college. The mean Mini Mental State Exam (MMSE) score was 16, with a range of 1 to 29. Eighty-five percent scored 24 or lower, indicating some degree of cognitive impairment. The remaining 15% were cognitively intact. All but one participant could use each scale to rate their pain. Concurrent validity of the VDS, NRS, and IPT was supported with Spearman rank correlation coefficients ranging from .78 to .86 in the cognitively impaired group. The FPS, however, demonstrated weak correlations with other scales when used with the impaired group, ranging from .48 to .53. In the cognitively intact group, strong correlations ranging from .96 to .97 were found among all of the scales. Test-retest reliability at a 2-week interval was acceptable in the cognitively intact group (Spearman rank correlations ranged from .67 to .85) and unacceptable for most scales in the cognitively impaired group (correlations ranged from .26 to .67). When asked about scale preference, both the cognitively impaired and the intact groups preferred the IPT and the VDS. This study revealed that cognitive impairment did not inhibit participants' ability to use a variety of pain intensity scales, but the stability issue must be considered.

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

“…The findings showed that patients with mild or moderate CI can use pain intensity scales to report pain reliably and validly but the qualities of pain scales are varied (Chibnall & Tait, 2001;Closs et al, 2004;Scherder & Bouma, 2000;Taylor et al, 2005;Taylor & Herr, 2003;Ware et al, 2006). Generally, the VDS, the NRS, the FPS, the BS-21, and the CAS were proved to be feasible for assessing pain in the patients with none to mild or moderate CI.…”

“…Taylor and Herr (2003) compared the VDS, the NRS, the FPS, and the Iowa Pain Questionnaire (IPT) and reported that the FPS was the most preferred scale and had no failures in African-American old adults including the elderly with CI. In contrast, another two studies compared the similar scales in a primarily Caucasian sample, they found that the NRS and the VDS were the most preferred scales and had low errors in young and old adults without and with CI (Herr et al, 2004;Taylor et al, 2005), suggesting that the ethnic or culture differences might have an effect on scale preference. Therefore, the above evidences indicate that we need to consider cultural background when choosing and assessing pain assessment scales.…”

“…They found that test-retest reliability coefficients at a 2-week interval were acceptable and ranged from .52 to .83 in two groups but the weaker relationships were found in the elderly with CI group which might be related to the memory impairment in this group. In contrast, Taylor et al (2005) examined the VDS, the NRS, the FPS, and the IPT in the elderly with CI group and found that the test-retest reliability over a 2-week interval was unacceptable (rho = .26 -.67).…”

“…However, the FPS was also found having errors because some patients had less pain than the first face (Chibnall & Tait, 2001). In addition, the weak correlation was found between the FPS and other scales in the elderly with CI (.48 -.53) (Taylor et al, 2005). The Brief Pain Inventory (BPI) is a survey instrument originally for use with cancer patients and can be used to measure pain in other conditions (McGuire et al, 2004).…”

“…The findings showed that patients with mild or moderate CI can use pain intensity scales to report pain reliably and validly but the qualities of pain scales are varied. Taylor et al (2005) evaluated the VDS, the NRS, the FPS, and the IPT in Caucasian old adults without and with CI. They found that the concurrent validity of these scales was good and both the elderly without and with CI groups were able to use these pain scales and preferred the IPT and the VDS, however, the test-retest reliability at a 2-week interval was unacceptable for most scales in the elderly with CI group and suggested that the stability issue in the elderly with CI must be considered in future studies.…”