Using probability vs. nonprobability sampling to identify hard-to-access participants for health-related research: costs and contrasts.

This article compares the recruitment costs and participant characteristics associated with the use of probability and nonprobability sampling strategies in a longitudinal study of older hemodialysis patients and their spouses. Contrasts were made of people who accrued to the study based on probability and nonprobability sampling strategies. Probability-based sampling was more time-efficient and cost-effective than nonprobability sampling. There were no significant differences between the respondents identified through probability and nonprobability sampling on age, gender, years married, education, work status, and professional job status. Respondents from the probability sample were more likely to be Protestant and less likely to be Catholic than those from the nonprobability sample. Respondents from the probability sample were more likely to be Black, whereas those from the nonprobability sample were more likely to be White. There are strengths and shortcomings associated with both nonprobability and probability sampling. Researchers need to consider representativeness and external validity issues when designing sampling and related recruitment plans for health-related research.

Predictors of patient treatment preferences and spouse substituted judgments: the case of dialysis continuation.

OBJECTIVES: To examine the factors predicting preferences for continued hemodialysis treatment among patients with endstage renal disease (ESRD) and to compare these factors to those predicting their spouses' predictions of patients' preferences (substituted judgments). DESIGN: Descriptive, cross-sectional. PARTICIPANTS: Total of 291 hemodialysis patients, aged 55 years and older, and their spouses. MEASUREMENT: Hypothetical scenarios were designed to elicit preferences for dialysis continuation under various health conditions. Other measures included the Philadelphia Geriatric Center Negative Affect Scale, Kidney Disease Symptoms Scale, Brief Multidimensional Measure of Religiousness, single-item global subjective health and quality-of-life measures, 2-item fear of end-of-life suffering measure, and selected demographics. RESULTS: Patients' preferences and spouses' judgments were only moderately correlated (r = 0.33). Multiple regression analyses revealed that patients' preferences to continue dialysis were positively related to education, subjective quality of life, and religious participation and negatively related to months of ESRD treatment and fear of end-of-life suffering (R(2) = 0.15). Spouses' substituted judgments regarding patients' dialysis continuation preferences were positively related to African American race and spouses' perceptions of patients' quality of life and negatively related to months of ESRD treatment, spouses' perception of patients' negative affect, and spouses' own fear of end-of-life suffering. CONCLUSION: Patients and surrogates used different criteria in formulating judgments about continuation of life-sustaining treatment and had different perceptions about the patients' condition. Furthermore, the substituted judgments of spouses were influenced by their own characteristics. These processes may explain inaccurate substituted judgments.

Spouse as health care proxy for dialysis patients: whose preferences matter?

PURPOSE: We examined the extent to which the substituted judgments made by spouses of patients with end-stage renal disease actually reflect patient preferences. DESIGN AND METHODS: We used data from 291 couples to compare dialysis patients' preferences for continuing hemodialysis under a variety of hypothetical situations with both substituted judgment data from spouses and information about spouses' own preferences. RESULTS: Substituted judgments were more highly related to spouses' preferences than to patients' preferences. IMPLICATIONS: Findings raise questions about the extent to which the moral principle of patient autonomy should guide decision making at the end of life.

Chemotherapy use among Medicare beneficiaries at the end of life.

BACKGROUND: Although many observers believe that cancer chemotherapy is overused at the end of life, there are no published data on this. OBJECTIVE: To determine the frequency and duration of chemotherapy use in the last 6 months of life stratified by type of cancer, age, and sex. DESIGN: Retrospective cohort analysis. SETTING: Administrative databases from Massachusetts and California. PATIENTS: All Medicare patients who died of cancer in Massachusetts and 5% of Medicare cancer decedents in California in 1996. MEASUREMENTS: Use of intravenous chemotherapy agents, chemotherapy administration, or medical evaluation for chemotherapy from Medicare billing data for each patient in 30-day periods from the date of death backward. RESULTS: In Massachusetts, 33% of cancer decedents older than 65 years of age received chemotherapy in the last 6 months of life, 23% in the last 3 months, and 9% in the last month. In California, the percentages were 26%, 20%, and 9%, respectively. Chemotherapy use greatly declined with age. Chemotherapy use was similar for patients with breast, colon, and ovarian cancer and those with cancer generally considered unresponsive to chemotherapy, such as pancreatic, hepatocellular, or renal-cell cancer or melanoma. Patients with types of cancer that are unresponsive to chemotherapy had shorter duration of chemotherapy use. CONCLUSION: Among patients who died of cancer, chemotherapy was used frequently in the last 3 months of life. The cancer's responsiveness to chemotherapy does not seem to influence whether dying patients receive chemotherapy at the end of life.

Managed care, hospice use, site of death, and medical expenditures in the last year of life.

BACKGROUND: We examined deaths of Medicare beneficiaries in Massachusetts and California to evaluate the effect of managed care on the use of hospice and site of death and to determine how hospice affects the expenditures for the last year of life. METHODS: Medicare data for beneficiaries in Massachusetts (n = 37 933) and California (n = 27 685) who died in 1996 were merged with each state's death certificate files to determine site and cause of death. Expenditure data were Health Care Financing Administration payments and were divided into 30-day periods from the date of death back 12 months. RESULTS: In Massachusetts, only 7% of decedents were enrolled in managed care organizations (MCOs); in California, 28%. More than 60% of hospice users had cancer. Hospice use was much lower in Massachusetts than in California (12% vs 18%). In both states, decedents enrolled in MCOs used hospice care much more than those enrolled in fee-for-service plans (17% vs 11% in Massachusetts and 25% vs 15% in California). This pattern persisted for those with cancer and younger (aged 65-74 years) decedents. Decedents receiving hospice care were significantly (P<.001 for both) less likely to die in the hospital (11% vs 43% in Massachusetts and 5% vs 43% in California). Enrollment in MCOs did not affect the proportion of in-hospital deaths (those enrolled in fee-for-service plans vs MCOs: 40% vs 39% in Massachusetts; and 37% vs 34% in California). Expenditures in the last year of life were $28 588 in Massachusetts and $27 814 in California; about one third of the expenditures occurred in the last month before death. Hospital services accounted for more than 50% of all expenditures in both states, despite 77% of decedents being hospitalized in Massachusetts and just 55% being hospitalized in California. Among patients with cancer, expenditures were 13% to 20% lower for those in hospice. CONCLUSIONS: Medicare-insured decedents in California were more than 4 times more likely to be enrolled in MCOs, were 50% more likely to use a hospice, and had a 30% lower hospitalization rate than decedents in Massachusetts, yet there are few differences in out-of-hospital deaths or expenditures in the last year of life. However, patients with cancer using hospice did have significant savings.