Development and psychometric evaluation of the Pain Assessment in Advanced Dementia (PAINAD) scale.

OBJECTIVES To develop a clinically relevant and easy to use pain assessment tool for individuals with advanced dementia that has adequate psychometric properties. DESIGN Instrument development study using expert clinicians and behavioral observation methods. Measurement of sensitivity of the instrument to detect the effects of analgesic medications in a quality improvement activity. SETTING Inpatient dementia special care units in a Veterans Administration Medical Center. PARTICIPANTS Nineteen residents with advanced dementia who were aphasic or lacked the ability to report their degree of pain and six professional staff members. Additionally, data from medical records of 25 residents who were receiving pain medications as required (PRN) were collected. MEASUREMENTS Based on the literature review, related assessment tools and consultation with expert clinicians, a five-item observational tool with a range of 0 to 10 was developed. The tool, Pain Assessment in Advanced Dementia (PAINAD), was compared with the Discomfort Scale and two visual analog scales (discomfort and pain) by trained raters/expert clinicians in the development study, and used for detection of analgesic efficacy in a quality improvement activity. RESULTS Adequate levels of interrater reliability were achieved between dyads of the principal investigator with each clinical research rater and between two raters. PAINAD had satisfactory reliability by internal consistency with a one factor solution. PAINADthe Discomfort Scale-Dementia of Alzheimer Type (DS-DAT) were significantly correlated, providing evidence of construct validity. PAINAD detected statistically significant difference between scores obtained before and after receiving a pain medication. CONCLUSIONS The PAINAD is a simple, valid, and reliable instrument for measurement of pain in noncommunicative patients. Since the patient population used for its development and testing was limited to a relatively small number of males, further research is needed before it can be universally recommended.