It is believed by many researchers that little attention has been given to patients' perceptions of the impact of chronic pain on their lives. In recognition of this need, G. Frank Lawlis, C. Edward McCoy, and David K. Selby developed the Dallas Pain Questionnaire (DPQ) to assess the amount of chronic pain that affects four aspects (daily activities, work-leisure activities, anxiety-depression, and social interest) of the patients' lives. The present study, conducted to validate the DPQ's statistical properties, first reviews the literature addressing the various theories and varieties of pain, its opiates, and the two current approaches to quantify pain. This study included a total of 143 subjects. Clinical subjects were 104 inpatients in the Spinal and Chronic Pain Center at Medical Arts Hospital and 15 chronic pain outpatients released to work. Normal subjects consisted of staffing personnel (n = 13) and flight assistance employees (U = 11)- Both clinical and normal groups completed the DPQ. The Minnesota Multiphasic Personality Inventory (MMPI) was administered only to the clinical population. Results suggest that the DPQ is both externally reliable (stability reliability coefficient of .970) as well as an internally consistent instrument. Two factors emerged from factor structure analysis. Factor one (63.2% of variance) represents functional activities. Factor two (8.3% of variance) represents emotional capacities. A correlation analysis suggests the concurrent validity of the psychological and functional factors of the DPQ. A t-test demonstrated that chronic pain patients have significantly higher DPQ's scores than normals. Because these findings support its psychometric properties, the DPQ appears to have utility for clinical and research purposes. The findings, limitations, and implications of this study are detailed, as are suggestions for future research.

The purpose of this study was to validate the Spanish version of the Dallas Pain Questionnaire (DPQ). Not only does the DPQ offer the potential of statistical and clinical diagnostic value but also is easily interpretable across cultural lines. No such instrument has presently been validated for the Mexican-American population. A total of 81 Spanish speaking subjects participated in this study. Of these subjects, 56 were classified as chronic pain patients by nature of their medical diagnosis and duration of pain. The 25 normal subjects were family members of the chronic pain patients and members of the Northern New Mexico Hispanic community chosen at random. Hypothesis one predicted that reliability would be obtained on Spanish speaking populations based on test-retest with correlation coefficients of the items. The second hypothesis predicted that the Spanish DPQ would have content validity or consistent internal structure on those items that measure the trait or behavior of interest based upon factor analysis approaches and internal consistency measures. Hypothesis three predicted that the Spanish version of the DPQ would significantly correlate with the English version of the DPQ on all four factors. All four hypotheses were supported. The Spanish DPQ showed reliability over time based on test-retest. The statistics revealed an internally reliable test, alpha coefficient analysis and factor analysis. The validity was supported by significant correlations with the English DPQ and discrimination between chronic and nonchronic pain patients. While all four hypotheses were upheld, interpretation of the present findings should be moderated by recognition of the limitations of the studies. Future studies should test larger samples to improve confidence in the psychometric properties of the instrument. Still notable limitations of the questionnaire are that the Spanish DPQ is a form that is more accurately viewed as a global measure.