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Nicholas A Christakis

Publications and source records attributed to Nicholas A Christakis.

28 records · Page 2Linked to original sources
PubMed2002

Physician factors in the timing of cancer patient referral to hospice palliative care.

BACKGROUND: Although physicians state that patients ideally should receive hospice care for 3 months before death, the majority of patients survive < 1 month in hospice care. In the current study, the authors attempted to determine whether the attributes of referring physicians were associated with the survival of terminally ill cancer patients in hospice. METHODS: Using a prospective cohort study design, the authors observed the survival of 326 terminally ill cancer patients who were referred by 258 different physicians to 5 outpatient hospice programs in Chicago. The authors evaluated associations between patient, physician, and patient-physician relationship factors and patient survival. RESULTS: Of the 326 participating patients, 313 (96%) had known dates of death. For these patients, the median survival was 26 days. Controlling for patient demographic and disease factors, there were several physician factors found to be associated with the length of patient survival after hospice referral. For example, when a physician had referred > or = 2 patients to hospice care in the previous 3 months, the patient survived 17 days longer in hospice compared with those patients whose physician referred fewer patients to hospice. When a physician estimated patient survival accurately (estimate obtained at the time of referral), the patient lived 20 days longer in hospice compared with those patients whose physicians made inaccurate survival estimates. The practice specialty of the physician also was found to be associated with patient survival after hospice referral, with patients referred by general internists and geriatricians living 18 days longer in hospice compared with those patients who were referred by oncologists. CONCLUSIONS: In the current study, referring physician factors were found to be associated with the survival of terminally ill cancer patients after referral to hospice.

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PubMed2002

Racial, ethnic, and affluence differences in elderly patients' use of teaching hospitals.

OBJECTIVE: To understand the role of race, ethnicity, and affluence in elderly patients' use of teaching hospitals when they have that option. METHODS: Using a novel data set of 787,587 Medicare patients newly diagnosed with serious illness in 1993, we look at how sociodemographic factors influence whether patients use a teaching hospital for their initial hospitalization for their disease. We use hierarchical linear models to take into account differences in the availability of teaching hospitals to different groups. These models look within groups of people who live in the same county and ask what demographic factors make an individual within that county more or less likely to use a teaching hospital. RESULTS: We find that blacks are much more likely than whites to use teaching hospitals (odds ratio [OR], 1.75; 95% confidence interval [95% CI], 1.73 to 1.77). However, Hispanics and Asian-Americans are less likely to use teaching hospitals than are whites (Hispanic OR, 0.92; 95% CI, 0.88 to 0.97; Asian-American OR, 0.89; 95% CI, 0.82 to 0.97). Medicaid patients are less likely to use teaching hospitals (given their opportunities) than are non-Medicaid recipients (OR, 0.91; 95% CI, 0.90 to 0.92). And we find a curvilinear relationship with affluence, with those in the poorest and those in the wealthiest neighborhoods most likely to use a teaching hospital. CONCLUSION: The use of teaching hospitals is more complex that heretofore appreciated. Understanding why some groups do not go to teaching hospitals could be important for the health of those groups and of teaching hospitals.

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PubMed2002

Initial assessment of a new instrument to measure quality of life at the end of life.

PURPOSE: We conducted this study to pilot a new multidimensional instrument to assess the quality of life at the end of life. METHODS: Items were derived from focus groups and a national survey identifying attributes of the quality of dying. Fifty-four items measured on a five-point Likert scale covered six domains. We administered the instrument to equal numbers of Veteran's Administration (VA) and university medical center outpatients with advanced serious illness. We assessed psychometric properties using factor analysis. RESULTS: Two hundred patients completed the instrument (response rate, 85%). Diagnoses included cancer (64%), congenital heart failure (CHF) (19.5%), end-stage renal disease (ESRD) (10%) and chronic obstructive pulmonary disease (COPD) (6.5%). Seventy-four percent were male, 64% were caucasian, and 34% African American. Item reduction and factor analysis yielded a final instrument with 24 items in 5 distinct domains (overall Cronbach a = 0.83). The first factor (6 items; a = 0.84) measured a sense of completion, particularly through contributions to others. The second factor (7 items; alpha = 0.77) measured relations with the health care system. The third factor (6 items; alpha = 0.77) measured preparation. The fourth factor (4 items; alpha = 0.77) measured symptom severity, and the final factor (2 items; alpha = 0.60) measured affective social support. CONCLUSIONS: We have developed a new instrument to measure the quality of life at the end of life that assesses empirically derived domains that are of demonstrated importance to dying patients, is acceptable to a seriously ill population, and exhibits excellent psychometric properties. Some items related to completion and preparation represent particularly new contributions to quality-of-life measurement.

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PubMed2002

Care after the onset of serious illness: a novel claims-based dataset exploiting substantial cross-set linkages to study end-of-life care.

To date, there has not been a study using a large, nationally representative group of patients with serious illness who are at risk for hospice use and who are followed forward in time to understand the determinants of hospice use. In this paper, we outline the development of a large new cohort of 1,221,153 Medicare beneficiaries newly diagnosed with 1 of 13 serious conditions in 1993, a cohort that can be used to study end-of-life care in the United States. In describing our methods, we illustrate the possible utility of Medicare claims for end-of-life research. The members of our cohort are followed forward for hospice and other health care use through December 1997, and for mortality through June 1999. Medicare claims data on their inpatient and outpatient hospital use is also collected. Based on the ZIP Codes and counties in which cohort members lived, we were also able to characterize the health care markets of cohort members, as well as obtain other socioeconomic information about them. Information about cohort member's health care providers is also available. Detailed health information about cohort members' spouses was also collected. We conclude by highlighting the types of analyses that can be conducted in this data set.

Cohort Studies↗
PubMed2002

Disease-specific patterns of hospice and related healthcare use in an incidence cohort of seriously ill elderly patients.

There appears to be significant heterogeneity across diseases in their patterns of health care use at the end of life. We use a new, nationally representative sample of patients diagnosed in 1993 with 13 serious diseases to demonstrate this variation in rates of inpatient, outpatient, and hospice utilization. The diseases are: cancer of the lung, colon, pancreas, urinary tract, liver or biliary tract, head or neck, or central nervous system, as well as leukemia or lymphoma, stroke, congestive heart failure, hip fracture, or myocardial infarction. We present disease-specific rates of: length of stay, interhospital transfer, outpatient visits in the year before and 3 years after diagnosis, death within 4 years, and gender-specific hospice use rates among decedents. Among decedents with noncancer diagnoses, rates of hospice use vary from 5.9% to 8.7%. Among decedents with cancer diagnoses, rates vary from 15.2% to 35.2%. For the cohort overall, 14.2% of male decedents and 12.4% of female decedents used hospice. Patterns of end-of-life care vary substantially according to diagnosis.

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PubMed2002

Construct validity of medicare chemotherapy claims: the case of 5FU.

BACKGROUND: The elderly are under represented in clinical trials of cancer therapy and the elderly who are enrolled may be unrepresentative. OBJECTIVE: To assess whether Medicare claims data might be used to understand the benefits and tolerance of chemotherapy in the general elderly population, the construct validity of Medicare 5FU claims for elderly colon cancer patients within the SEER-Medicare data set was determined. METHODS: In this validation study of Medicare chemotherapy claims from the linked the SEER-Medicare data set, the patterns of 5FU chemotherapy claims were evaluated for an incident cohort of elderly colon cancer patients (n = 15,039) during the 13 months following their diagnosis. Patterns of Medicare National Claims History (NCH) 5FU claims were evaluated with respect to prespecified patient-level disease and demographic factors from the data set. RESULTS: Twenty-two percent of patients had at least one detectable 5FU claim during the observation period. Among those patients, the median dose of 5FU was 1000 mg, the median interval between 5FU claims was 7 days, and the median number of claims during this period was 24. Multivariate regression revealed expected associations between demographic and disease factors and the likelihood of having a Medicare NCH 5FU claim. With increasing cancer stage, patients' likelihood of having a 5FU claim increased. Younger patients, married patients, white patients, patients with low comorbidity, and patients living in urban and less impoverished regions were each more likely to have 5FU claims. CONCLUSION: Because their pattern is consistent with the standard of medical care and with previously described associations with disease and demographic factors, it was concluded that Medicare NCH claims for 5FU administration in the SEER-Medicare data set exhibit construct validity. Criterion validation studies with an external gold standard should be pursued to determine the sensitivity and specificity of chemotherapy codes in the Medicare NCH files.

Adenocarcinoma↗
PubMed2002

The lack of effect of market structure on hospice use.

OBJECTIVE: To describe the relative importance of health care market structure and county-level demographics in determining rates of hospice use. DATA SOURCES: Medicare claims data for a cohort of elderly patients newly diagnosed with lung cancer, colon cancer, stroke, or heart attack in 1993, followed for up to five years, and linked to Census and Area Resource File data. STUDY DESIGN: Variation between markets in rates of hospice use by patients with serious illness was examined after taking into account differences in individual-level data using hierarchical linear models. The relative explanatory power of market-level structure and local demographic variables was compared. DATA COLLECTION METHODS: The cohort was defined within the Medicare hospital claims data using validated algorithms to detect incident cases of disease with a three-year lookback. Use of hospice was determined by linkage at an individual level to the Standard Analytic Files for Hospice through 1997. Individual-level data was linked to the Area Resource File using county identifiers present in the Medicare claims. PRINCIPAL FINDINGS: There is substantial variation in hospice use across markets. This variation is not explained by differences in the major components of health care infrastructure: the availability of hospital, nursing home, or skilled nursing facilities, nor by the availability of HMOs, doctors, or generalists. CONCLUSIONS: Intercounty heterogeneity in hospice use is substantial, and may not be related to the set-up of the medical care system. The important local factors may be local preferences, differences in the particular mix of services provided by local hospices, or differences in community leadership on end of life-issues; many of these differences may be amenable to educational efforts.

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