Patients with cancer and next-of-kin response comparability on physical and psychological symptom well-being: trends and measurement issues.

Next of kin (NOK) play an integral role in fostering optimal quality of life in symptomatic patients who are coping with cancer in the home setting. Often when patients in advanced stages of cancer are no longer able to meaningfully communicate their illness and symptom needs, healthcare professionals turn to NOK to provide sound estimates of patients' symptom experiences. This overview is based on 37 research studies written between 1987 and 2002 and updates an earlier overview of 13 studies on patient-NOK response comparability. The purpose is to, first, promote a better comprehension of methodologies and statistical techniques commonly employed to measure patterns of response comparability (or levels of agreement) between patient self-reports and NOK estimates on patient quality-of-life experiences of physical or symptom and emotional or psychological well-being. The second aim is to identify conditions where NOK may pose as reasonably accurate judges of patients' health-related quality of life, particularly symptom experiences arising from various diagnoses, including cancer. Third, subsequent to identifying the gaps in current research knowledge and limitations in study designs, recommendations for statistical and methodological techniques are outlined.