Joan M. Romano

Comparative reliability and validity of chronic pain intensity measures

Reliable and valid measures of pain are essential for conducting research on chronic pain. The purpose of this longitudinal study was to compare the reliability and validity of several measures of pain intensity. One hundred twenty-three patients with chronic pain were administered telephone interview versions of 0-10 scales of current, worst, least and average pain, immediately prior to beginning a multidisciplinary treatment program. The measures were administered again to these subjects 2 weeks (n=108), 1 month (n=106) and 2 months (n=105) after the end of treatment. The validity (defined as ability to detect changes in pain intensity over the course of treatment up to the 2-month follow-up assessment) and reliability (defined as stability over time in the 2 months after treatment) of these four measures and of composite combinations of these measures were examined. Contrary to prediction, the composite measures did not show a statistically significant superiority to the individual ratings in terms of their ability to detect change in pain intensity from pre-treatment to various points after treatment. The composite scores did, however, show greater stability than did the individual ratings after treatment. The practical conclusions of this study are; (1), individual 0-10 pain intensity ratings have sufficient psychometric strengths to be used in chronic pain research, especially research that involves group comparison designs with relatively large sample sizes, but, (2), composites of 0-10 ratings may be more useful when maximal reliability is necessary, (e.g. in studies with relatively small sample sizes, or in clinical settings where monitoring of changes in pain intensity in individuals is needed).

Coping with chronic pain: a critical review of the literature

&NA; A growing number of investigators have used models of stress and coping to help explain the differences in adjustment found among persons who experience chronic pain. This article reviews the empirical research which has examined the relationships among beliefs, coping, and adjustment to chronic pain. Although preliminary, some consistent findings are beginning to emerge. For example, patients who believe they can control their pain, who avoid catastrophizing about their condition, and who believe they are not severely disabled appear to function better than those who do not. Such beliefs may mediate some of the relationships between pain severity and adjustment. Although coping strategies appear to be associated with adjustment in chronic pain patients, methodological problems limit conclusions regarding the strenght and nature of this association. Our recommendations for future research include the development of coping and belief measures which: (1) do not confound different dimensions (e.g., coping, beliefs, and adjustment) in the same measure; (2) assess specific (rather than composite) constructs; (3) are psychometrically sound; and (4) assess behavioral coping strategies more objectively. We also recommend a greater use of experimental research designs to examine causal relationships among appraisals, coping, andadjustment.

Changes in beliefs, catastrophizing, and coping are associated with improvement in multidisciplinary pain treatment

To examine the associations between changes in cognitions and coping and multidisciplinary pain treatment outcomes, the authors had 141 patients with chronic pain complete measures of adjustment, beliefs, catastrophizing, and coping; in addition, their significant others rated patient physical functioning at pretreatment, posttreatment, and 6- and 12-month follow-ups. Decreases in guarding and resting and in the belief that pain signals damage were associated with decreases in patient disability. Increases in perceived control over pain and decreases in catastrophizing and in the belief that one is disabled were associated with decreases in self-reported patient disability, pain intensity, and depression. The results are consistent with the hypothesis, derived from cognitive-behavioral models of chronic pain, that the outcomes of multidisciplinary pain treatment are associated with changes in patient cognitions and coping responses.

The chronic pain coping inventory: development and preliminary validation

&NA; This paper describes the development and validation of a measure of strategies used by patients to cope with chronic pain, the Chronic Pain Coping Inventory (CPCI). A 104‐item measure of pain coping responses and 3 measures of functioning were completed by 176 chronic pain patients. Two‐week retest data were provided by 111 of these patients. Item and scale analyses resulted in a 65‐item measure that assessed 11 pain coping dimensions. This inventory was then cross‐validated in a second sample of chronic pain patients (n = 78), who also completed a measure of pain‐related distress. The significant others (typically, spouses) of patients in the second sample rated patients on a significant‐other version of the CPCI and on other measures of patient functioning. The results support the reliability of the CPCI scales. Four scales (Guarding, Resting, Asking for Assistance, and Task Persistence) predicted patient‐ and significant other‐reported patient adjustment. Eight scales (Guarding, Opioid Medication Use, NSAID Use, Sedative‐Hypnotic Medication Use, Resting, Asking for Assistance, and Exercise/ Stretch) demonstrated moderate‐to‐strong relationships between patient and significant‐other versions, further supporting their validity.

Correlates of Improvement in Multidisciplinary Treatment of Chronic Pain

Although multidisciplinary pain programs have been demonstrated to be effective, the processes of improvement have yet to be clarified. Cognitive-behavioral models posit that improvement is due, in part, to changes in patient pain beliefs and coping strategies. To test the relationships between treatment outcome and changes in beliefs and coping strategies, 94 chronic pain patients completed measures of physical and psychological functioning, health care utilization, pain beliefs, and use of pain coping strategies at admission and 3 to 6 months after inpatient pain treatment. Improved functioning and decreased health care use were associated with changes in both beliefs and cognitive coping strategies. However, changes in some coping strategies, such as exercise and use of rest, were not associated with improvement.

Chronic pain patient-spouse behavioral interactions predict patient disability

&NA; Based on behavioral theory, it has been hypothesized that spouse solicitous responses to the pain behaviors of chronic pain patients may contribute to the maintenance of pain behaviors and disability. Self‐report data support this hypothesis, but direct observational measures have not been used to study this association. In this study, 50 chronic pain patients and their spouses were videotaped while engaging in common household activities, and patient pain behaviors and spouse solicitous behaviors were coded from the tapes. Spouse solicitous responses to non‐verbal pain behaviors were significant predictors of physical disability in the more depressed patients, and were significant predictors of rate of non‐verbal pain behavior in patients who reported greater pain. Spouse sulicitous responses did not predict psychosocial dysfunction or total self‐reported pain behaviors. The results support behavioral theory and indicate the need for further study of the association between spouse solicitousness and patient pain behaviors/disability.

Self-report screening measures for depression in chronic pain patients

Depression is prevalent among chronic pain patients, yet little is known about the ability of various self-report measures to detect this disorder in this population. This study investigated the relationship of several self-report depression scales (Beck Depression Inventory-standard and short forms, MMPI Depression, Depression subtle, and Depression obvious scales, and the Zung Self-Rating Depression Scale) to clinician DSM-III diagnoses of major depressive disorder in 40 chronic pain patients. Thirty percent of the Ss met criteria for major depression. Sensitivity and specificity values obtained for each scale are presented. The standard and short forms of the Beck Depression Inventory and the Zung Self-Rating Depression Scale showed good sensitivity and specificity and were comparable in detecting major depression in this sample.

The relationship of attachment style to depression, catastrophizing and health care utilization in patients with chronic pain

Attachment theory and research suggest that patterns of interpersonal relationships may be important determinants of illness behavior, care seeking, and treatment response in individuals with chronic health problems, including chronic pain. Attachment styles have been shown to be associated with psychological adjustment in the context of chronic illness, but little research has been conducted so far examining these relationships in patients with chronic pain. We assessed 111 patients with chronic pain participating in a multidisciplinary pain treatment program to determine if attachment style is associated with pain, depression, catastrophizing and physical disability at pre‐treatment and 12‐month follow‐up, and with change in health care utilization pre‐treatment to follow‐up. At both pre‐treatment and follow‐up, fearful attachment style was associated with significantly greater depression and catastrophizing, and secure attachment was associated with significantly lower levels of depression. Preoccupied attachment style was associated with greater than weekly pain‐related visits at 12 months follow‐up, even after controlling for depression, catastrophizing and pre‐treatment pain‐related health care utilization. The findings suggest that attachment style may be a useful construct for examining factors affecting adjustment and treatment response of patients with chronic pain.

Validity of the Sickness Impact Profile Roland scale as a measure of dysfunction in chronic pain patients.

&NA; This study examined the reliability and validity of the Roland scale (taken from the Sickness Impact Profile: SIP) as a measure of dysfunction among chronic pain patients. One hundred forty‐four subjects completed the SIP when they were screened for admission to an inpatient pain management program. One hundred sixteen subjects were subsequently re‐administered the SIP at admission to inpatient treatment. A 3‐month post‐treatment administration of the SIP was performed for 52 of these subjects. Roland scale scores were calculated from the SIP for each patient. Test‐retest stability coefficients indicated that the SIP Roland scale was generally as reliable as the SIP Total, Physical, and Psychosocial scale scores. Consistent with previous research, correlational analyses indicated that the SIP Roland scale is strongly associated with the SIP Physical but not the SIP Psychosocial scale. The SIP Roland scale and the other SIP scales demonstrated similar sensitivity to changes associated with multidisciplinary inpatient treatment for chronic pain. Finally, the pattern of relationships between the SIP Roland scale and several pain‐related measures supported the concurrent validity of the SIP Roland scale. The results of the analyses were very similar for patients presenting with and without low back pain. The study supports the reliability and validity of the SIP Roland scale items for assessing dysfunction of chronic pain patients with pain in sites other than the low back as well as those with low back pain.

The use of multiple-item scales for pain intensity measurement in chronic pain patients

&NA; This study examined the relative predictive validities of several measures of pain intensity. Forty chronic pain patients completed 6–14 days worth of hourly pain ratings, which were averaged to obtain a measure of actual average pain intensity. These patients then made ratings, on 101‐point numerical rating scales, of worst, least, and usual pain during the previous 2 wks, and of their current pain. A series of correlation coefficients were computed and regression analyses were performed to determine the individual or composite measures that best predicted actual average pain intensity. Consistent with previous research, the best single predictor of actual average pain intensity was patient rating of least pain in the previous 2 wks. Of all possible composites of usual, least, worst, and current pain ratings, the arithmetic mean of least and usual pain had the strongest relationship to actual average pain. The inclusion of ratings of most pain or current pain in any composite score actually weakened the relationship between the composite score and actual average pain intensity. These results suggest that, when clinicians or researchers wish to assess average pain among chronic pain patients, but cannot obtain multiple measures of pain over time, the most valid measure would be the arithmetic mean of patient‐recalled least and usual pain.