Cognitive impairment and its influence on pain and symptom assessment in apalliative care unit: development, of a Minimal Documentation System

Symptom assessment in the palliative care unit must consider the reduced ph ysical and mental status of the patients. Standardized instruments are ofte n not completed by patients with cognitive impairment. We tried to combine minimal burden for patients and staff with sufficient information content i n a Minimal Documentation System (MIDOS) for pain and symptom assessment in palliative care patients. From January to July 1998, 108 patients (123 consecutive admissions) with a mean age of 63 years (range 32-87 years) were admitted to the palliative c are unit. Pain was reported as the reason for admission in 70% of the patie nts, and 71% were treated with opioids. Using a cut-off point of 20/21, 35% of the patients were impaired in the Mini Mental Stale Examination (MMSE). The number of missing values in the Brief Pain Inventory (BPI) and the qua lity-of-life questionnaire SF-12 correlated highly with each other and with the MMSE sum score, hut not with the summary scores of BPI or SF-12. Only 31 patients completed the SF-12 quality-of-life questionnaire. Age was not correlated to MMSE scores, and neither were opioid doses for 26 patients wi th slow- release oral morphine or for 20 patients with transdermal fentanyl . Only a minority of patients was able to use the numerical scale for symptom s other than pain, though most patients were able to score symptom intensit y on the verbal categorical scale. Pain and symptom assessments were perfor med by the physician for 17% Of the patients at admission, and for 16% of t he follow-up controls because self-assessment was not possible. In this study, cognitive impairment prevented symptom assessment with longe r and more complicated instruments such as the SF-12 in a large number of t he patients admitted to the palliative care unit. Assessment instruments fo r patients with advanced disease must provide simple categorical scales and the possibility of being administered by interview.