Use of Medicare services by elderly residents of Puerto Rico

OBJECTIVES: We describe hospitalization rates among Medicare beneficiaries resident in Puerto Rico compared to beneficiaries in the mainland U.S., in 1999. METHODS: A cross-sectional analysis using Medicare Denominator and hospitalization files. RESULTS: The rate ratio (PR/U.S.) of age, gender-adjusted hospitalizations among elderly Medicare beneficiaries with Part A coverage was 0.78, compared with 0.92 among beneficiaries with both Part A and Part B coverage. Among the latter, the rate ratios were 0.78 for surgical admissions, 1.08 for low-variation medical conditions, and 0.97 for high variation medical conditions. They were higher for younger elderly beneficiaries. CONCLUSIONS: Rates of hospitalization in Puerto Rico may be lower, the same or exceed those of the mainland U.S. depending on the age of the beneficiary and the type of hospitalization.

Hospice use in Medicare managed care and fee-for-service systems.

OBJECTIVE: To examine whether patterns of hospice use by older Medicare beneficiaries are consistent with the differing financial incentives in Medicare managed care (MC) and fee-for-service (FFS) settings. Specifically, are use patterns consistent with incentives that might encourage hospice use for MC enrollees and discourage hospice use for FFS enrollees? STUDY DESIGN: One-year study of hospice use by Medicare beneficiaries dying in 1996. PATIENTS AND METHODS: Medicare enrollment and hospice administrative data were used to examine hospice use before death for all elderly individuals residing in 100 US counties with high MC enrollment in 1996. Age-, sex-, and race-adjusted rate of hospice use and length of stay in hospice are compared between FFS and MC enrollees across and within (when possible) the 100 counties. RESULTS: Rates of hospice use were significantly higher for MC enrollees than for FFS enrollees (26.6 vs 17.0 per 100 deaths; P < .001). These differences persisted within age, sex, and race groups but were not related to area MC enrollment rate or the amount of money paid to managed care organizations. Age-, sex-, and race-adjusted differences were observed in 94 of 100 counties. Length of stay in hospice was marginally longer for MC enrollees than for FFS enrollees (median, 24 vs 21 days; P < .0001). CONCLUSIONS: System of care is an important determinant of hospice use in the elderly Medicare population.

Monitoring the health status and impact of treatment on Americans: the Medicare Beneficiary Health Status Registry.

OBJECTIVE: A major new survey program, the Medicare Beneficiary Health Status Registry (MBHSR), has been proposed to improve the monitoring of the health status of Medicare beneficiaries. The MBHSR would collect data by mail with telephone follow up of nonrespondents to permit economical assessment of a total Registry of approximately 200,000 Medicare beneficiaries, approximately 54,000 of whom would be surveyed in any given year. (Surveys would be conducted of samples of new enrollees who would be reinterviewed every five years.) METHOD: To assess the feasibility of that approach, a field test was conducted with a probability sample (n = 1,922) that comprised approximately equal numbers of new Medicare enrollees (aged, 65) and current beneficiaries (age range, 76-80). The field test was designed to assess the quality of the data that this design would produce. FINDINGS: Results indicate that the proposed design of the MBHSR could achieve response rates of approximately 80% among both age cohorts using a survey instrument that took 30 minutes to complete. Internal reliability of Activities of Daily Living, Instrumental Activities of Daily Living, Mobility, Mental Health Index, General Health, and Prostate Symptomatology scales ranged from 0.77 to 0.93. When measurements were repeated approximately 30 days after the initial survey, moderate to high levels of cross temporal correlation (range, 0.64-0.96) were found for most indexes, with the exception of prostate symptomatology. In addition, an earlier comparison of survey responses in the MBHSR field test to Medicare payment records indicated that the MBHSR field test obtained highly accurate reports of most of the major surgeries that were recorded in Medicare claims files. CONCLUSION: The design proposed for the MBHSR is feasible. If implemented, it should produce acceptably high rates of response and data quality.

Identifying persons with diabetes using Medicare claims data.

The objective of this study was to develop and validate a method for identifying Medicare beneficiaries with diabetes by using Medicare claims data. We used self-reports of diabetes status from participants in the Medicare Current Beneficiary Survey to determine disease status, and then we examined these participants' Medicare claims. Using self-reported diabetes status as the "gold standard," we determined the sensitivity, specificity, and reliability of claims data in identifying beneficiaries with diabetes. We found that to construct a method that is adequately sensitive (> or = 70%), highly specific (> or = 97.5%), and reliable (kappa > or = 0.80), researchers must combine information from different types of Medicare claims files, use 2 years of data to identify cases, and require at least 2 diagnoses of diabetes among claims involving ambulatory care. Since these criteria are met by more than one method, the choice of method should be governed by the goals of the research as well as more practical concerns.

Cost-effectiveness of vaccination against pneumococcal bacteremia among elderly people.

CONTEXT: Clinical, epidemiologic, and policy considerations support updating the cost-effectiveness of pneumococcal vaccination for elderly people and targeting the evaluation only to prevention of pneumococcal bacteremia. OBJECTIVE: To assess the implications for medical costs and health effects of vaccination against pneumococcal bacteremia in elderly people. DESIGN: Cost-effectiveness analysis of pneumococcal vaccination compared with no vaccination, from a societal perspective. SETTING AND PARTICIPANTS: The elderly population aged 65 years and older in the United States in 3 geographic areas: metropolitan Atlanta, Ga; Franklin County, Ohio; and Monroe County, New York. MAIN OUTCOME MEASURES: Incremental medical costs and health effects, expressed in quality-adjusted life-years per person vaccinated. RESULTS: Vaccination was cost saving, ie, it both reduced medical expenses and improved health, for all age groups and geographic areas analyzed in the base case. For people aged 65 years and older, vaccination saved $8.27 and gained 1.21 quality-adjusted days of life per person vaccinated. Vaccination of the 23 million elderly people unvaccinated in 1993 would have gained about 78000 years of healthy life and saved $194 million. In univariate sensitivity analysis, the results remained cost saving except for doubling vaccination costs, including future medical costs of survivors, and lowering vaccination effectiveness. With assumptions most unfavorable to vaccination, cost per quality-adjusted life-year ranged from $35 822 for ages 65 to 74 years to $598 487 for ages 85 years and older. In probabilistic sensitivity analysis, probability intervals were more narrow, with less than 5% probability that the ratio for ages 85 years and older would exceed $100000. CONCLUSIONS: Pneumococcal vaccination saves costs in the prevention of bacteremia alone and is greatly underused among the elderly population, on both health and economic grounds. These results support recent recommendations of the Advisory Committee on Immunization Practices and public and private efforts under way to improve vaccination rates.

The quality of health data obtained in a new survey of elderly Americans: a validation study of the proposed Medicare Beneficiary Health Status Registry (MBHSR).

The Medicare Beneficiary Health Status Registry (MBHSR) is a proposed new survey program that would collect health status indicators annually from large probability samples of Medicine beneficiaries. For reasons of economy, the MBHSR would use mail survey procedures with telephone follow-up of nonrespondents. Because of concerns about response rates and the validity and reliability of the data obtained by such methods, a large-scale (N = 1,922) field test was conducted. The field test assessed the validity of MBHSR survey reports of past medical treatment and conditions by comparing those reports with Medicare claims data. It assessed the (internal) reliability of MBHSR survey responses by comparing responses with logically related survey questions from the MBHSR. Analyses indicate that the MBHSR survey procedures using a combination of mail data collection with telephone follow-up of nonrespondents produced relatively high levels of sensitivity and specificity in identifying medical treatments and procedures previously recorded in Medicare claims data. In addition, the MBHSR Field Test obtained, in general, relatively high levels of internal consistency in survey reports.

Use of eye care services among the 1991 Medicare population.

PURPOSE: To determine the use of eye care services by type of provider (ophthalmologist, optometrist, and non-ophthalmologist physician) in the Medicare population. METHODS: As a basis for characterizing eye conditions and ophthalmic services among a population 65 years of age and older, 1991 claims from a representative 5% sample of Medicare beneficiaries were analyzed using a previously described classification scheme. Analysis was specifically conducted by type of provider as well as by the service provided. RESULTS: Almost one half of the approximately 30 million Medicare beneficiaries 65 years of age or older received eye care services in 1991, resulting in more than 35,000,000 visits (claims). Ophthalmologists provided services to 71% of this eye care population, and optometrists to 22%; 36% of this population received ophthalmic-related services from other providers, and 14% from only other providers (commonly for eye lid dermatitis and tumors). Cataract was the most common condition, accounting for 41% of visits to ophthalmologists (and 1.2 million cases of surgery), glaucoma accounted for 19% of visits, and retinal diseases for 14%. The visit percentages for optometrists are 58%, 8%, and 11%, respectively. Ophthalmic examination and evaluation accounted for 63% of the 28,000,000 paid ophthalmologists' procedures, and 58% of the 5,500,000 optometrists' procedures. CONCLUSION: Optometrists and physicians other than ophthalmologists were the sole providers of ophthalmic-related services to a large percentage of beneficiaries who received eye care in 1991. Within the universe of service provided by ophthalmologists, the majority of all care consisted of evaluation and management services as opposed to surgical procedure-based care.

The use and costs of physician services for ophthalmic surgical procedures in 1988 and 1991.

BACKGROUND AND OBJECTIVE: To examine the change in volume and costs of physician services for ophthalmic surgical procedures associated with physician fee cuts. MATERIALS AND METHODS: The authors analyzed the physician claims (Part B) data for a 5% random sample of the Medicare population. Number, rate, average allowed charge, and total cost of physician services for ophthalmic surgical procedures were compared for 1988 and 1991. RESULTS: An estimated 3.1 million (98 per 1000) ophthalmic surgical procedures were performed on Medicare beneficiaries in 1991, compared with 2.3 million (76 per 1000) in 1988. There was a 35% increase in number and a 28% increase in rate. The average allowed charge for these services decreased by 26% ($1155 vs $852 per procedure), with an overall cost of $2.6 billion in both years. CONCLUSION: A reduction in fee for physician services for ophthalmic surgical procedures from 1988 to 1991 was associated with an increase in the volume of the services. The overall costs of physician services for ophthalmic surgical procedures remained consistent between the two years.

Use of Medicare data to identify incident breast cancer cases.

Surveillance, Epidemiology and End Results (SEER) data from the National Cancer Institute (NCI) provide reliable information about cancer incidence. However, because SEER data are geographically limited and have a 2-year time lag, we evaluated whether Medicare data could provide timely information on cancer incidence. Comparing Medicare women hospitalized for breast cancer with women reported to SEER, Medicare data had high specificity (96.6 percent), yet low sensitivity (59.4 percent). We conclude that Medicare hospitalization data can identify incident cases for cancers that usually require inpatient hospitalization. For cancers that often only receive outpatient treatment, such as breast cancer, additional Medicare data, such as physician bills, are needed to understand the entirety of treatment practices.

Is there any connection between a second pneumonia shot and hospitalization among Medicare beneficiaries?

To learn whether the risk of revaccination in adults should limit its use, the authors investigated whether adverse events requiring hospitalization occurred in a group of Medicare enrollees revaccinated with pneumococcal polysaccharide vaccine. A prospective cohort analysis and case study of revaccinated people involved five percent of all elderly Medicare enrollees from 1985 through 1988, consisting of 66,256 people receiving one dose of vaccine and 1,099 receiving two doses. Comparison was made of the hospitalization rate within 30 days after revaccination and rates of singly vaccinated persons using discharge diagnosis for all those hospitalized during the 30 days after revaccination. No significant difference was found between the hospitalization rate of the revaccinated cohort and comparison group. No adverse reactions attributable to pneumococcal polysaccharide vaccine causing hospitalization were identified among 39 revaccinated persons who were hospitalized within 30 days of revaccination. Revaccination of elderly Medicare beneficiaries does not cause events serious enough to require hospitalization. Vaccination of persons according to the Public Health Service Immunization Practice Advisory Committee guidelines is recommended when the prior immunization status is unknown.

The burden and outcomes associated with dehydration among US elderly, 1991.

OBJECTIVES: Dehydration has been underappreciated as a cause of hospitalization and increased hospital-associated mortality in older people. This study used national data to analyze the burden and outcomes following hospitalizations with dehydration in the elderly. METHODS: Data from 1991 Medicare files were used to calculate rates of hospitalization with dehydration, to examine demographic characteristics and concomitant diagnoses associated with dehydration, and to analyze the contribution of dehydration to mortality. RESULTS: In 1991, 6.7% (731,695) of Medicare hospitalizations had dehydration listed as one of the five reported diagnoses, a rate of 236.2/10,000 elderly Medicare beneficiaries. In 1991, Medicare reimbursed over $446 million for hospitalizations with dehydration as the principal diagnosis. Older people, men, and Blacks had elevated risks for hospitalization with dehydration. Acute infections, such as pneumonia and urinary tract infections, were frequent concomitant diagnoses. About 50% of elderly Medicare beneficiaries hospitalized with dehydration died within a year of admission. CONCLUSIONS: Hospitalization of elderly people with dehydration is a serious and costly medical problem. Attention should be focused on understanding predisposing factors and devising strategies for prevention.

Hospitalizations with adverse events caused by digitalis therapy among elderly Medicare beneficiaries.

BACKGROUND: Digitalis products are among the agents most frequently prescribed to the elderly, yet previous studies have not provided age-, race-, and sex-specific rates of utilization of digitalis by this population. Estimates of the rate of hospitalization with an adverse reaction from digitalis therapy have varied considerably between systems relying on passive reports and those using active surveillance. METHODS: Medicare data from 1985 through 1991 and data from the 1987 National Medical Expenditure Survey were used to determine population-based estimates of the use of digitalis in elderly beneficiaries by age group, sex, and race. Hospitalization rates with an adverse event caused by digitalis therapy were calculated for those persons estimated to be using digitalis. Medicare data were used to identify the frequency of selected comorbidities among persons with an adverse event caused by digitalis therapy as well as the frequency of clinical manifestations associated with digitalis intoxication. RESULTS: Over 3 million Medicare beneficiaries were estimated to be using digitalis in 1987. A total of 202,011 hospitalizations with a coded adverse event caused by digitalis therapy were reported during the 7-year study period. Of persons estimated to be using digitalis, 8.53 per 1000 were hospitalized annually with an adverse event caused by digitalis therapy. Women, individuals with increasing age, and persons of black race, especially those with impaired renal function, were significantly (P < .05) more likely to experience hospitalization with an adverse event caused by digitalis therapy. CONCLUSION: This information may help identify categories of elderly patients who require more frequent monitoring to prevent adverse effects of digitalis therapy. Changes in the format of the hospital bill to include more diagnoses along with increased mandatory reporting of adverse drug events will improve the sensitivity of Medicare data for surveillance of adverse drug events.

Measuring the incidence of cancer in elderly Americans using Medicare claims data.

BACKGROUND: The Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute is the most frequently used and best estimate of the incidence of cancer in the United States. Although synthetic estimates based on the SEER information can be used to plan cancer prevention and intervention programs, the evaluation of these action programs and the monitoring of cancer incidence in states or other geographic areas requires information on the population for whom the program is directed. METHODS: The age-adjusted incidence of six cancers among persons 65 years of age and older for 1986-1987 living in the five states participating in the SEER program was compared with the incidence derived from hospitalization records contained in the Health Care Financing Administration's (HCFA) administrative data files. Age-adjusted incidence rates for 1990 developed from HCFA data for persons living in the nine SEER program areas were contrasted with the incidence rates for persons living in the rest of the United States and were developed for each of the 50 states and the District of Columbia. RESULTS: The comparison of the SEER and HCFA overall age-adjusted cancer incidence rates in the elderly for 1986-1987 showed that for four of the six cancers (breast, colon, lung, and corpus uteri) the rates differed by 5% or less. The HCFA derived rates were 6.37% and 7.65% greater than the SEER rates for prostate and esophagus cancer, respectively. The incidence of cancer between 1986 and 1990 was neither uniformly higher nor lower among elderly SEER program area residents compared with residents of the rest of the country. Incidence rates varied greatly among states for each of the cancers. CONCLUSIONS: HCFA administrative data can be used by states or other geographic units to monitor the incidence of cancer in the elderly as well as to plan and evaluate cancer prevention and intervention programs.

Continuing differences in the rates of percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery between elderly black and white Medicare beneficiaries.

Rates of hospitalization among black and white male and female Medicare beneficiaries, 65 years of age and older, for percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG) surgery and 30-day postadmission mortality rates were compared for the years 1986 through 1990. The age-adjusted rates of hospitalization for both procedures increased, and the 30-day postadmission mortality rates decreased in all four race-sex groups. The greatest increase in the procedure rates were seen among white males. Using two estimates of the prevalence of ischemic heart disease in the elderly to adjust for the need for these cardiac procedures, the 1990 rates of PTCA in white beneficiaries were between 1.55 and 1.99 times higher than the rates among black beneficiaries, and the rates of CABG surgery were between 1.68 and 2.16 times higher. These differences in revascularization rates raise questions about whether there is equal access to certain treatments in the two race groups.

Differences by race in the rates of procedures performed in hospitals for Medicare beneficiaries.

This study analyzes administrative data from the Medicare program to compare differences by race in the use of 17 major procedures performed in the hospital. In both 1986 and 1992, black beneficiaries were less likely than white beneficiaries to have received these procedures while hospitalized. The largest differences were seen for "referral-sensitive surgeries" such as percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, total knee replacement, and total hip replacement. These differences by race suggest that there are barriers to these services. In contrast, black beneficiaries were found to have substantially higher rates than white beneficiaries in the use of four procedures performed in the hospital: amputation of part of the lower limb, surgical debridement, arteriovenostomy, and bilateral orchiectomy. The types of procedures for which black beneficiaries have higher rates raise questions about whether there is a need for more comprehensive and continuous ambulatory care for the underlying health conditions associated with these procedures.

Appendectomy incidental to cholecystectomy among elderly Medicare beneficiaries.

To assess the risks of adverse outcomes after appendectomy incidental to cholecystectomy among elderly Medicare beneficiaries, 8,936 persons undergoing cholecystectomy with incidental appendectomy and 44,461 persons undergoing cholecystectomy without incidental appendectomy were studied. Controlling for age, race, gender and co-morbidity status, the risk for wound infection in persons with incidental appendectomy was 83 percent higher than in persons without incidental appendectomy (95 percent confidence interval, 1.53 to 2.18). The risks for having other adverse outcomes, including other infections, extensive intrahospital complications and mortality rate at 30 days, were also higher for the former group, although these differences were not statistically significant. In addition, the demographic characteristics and health status of persons undergoing cholecystectomy with incidental appendectomy with persons undergoing cholecystectomy only were compared. Males, persons of younger ages, of white race or with no co-morbid conditions, were significantly more likely to undergo cholecystectomy with incidental appendectomy. Variables to control for differences in the demographic characteristics and health status between persons receiving and not receiving incidental appendectomy were included in the regression models for adverse outcomes. However, these models may not completely control for differences between the two groups. As a result, the actual relationship between incidental appendectomy and adverse outcomes may be underestimated. The preventive effect of incidental appendectomy on morbidity and mortality rates from future instances of appendicitis was assessed by determining the remaining lifetime risk for acute appendicitis. For persons 65 to 69 years of age, 115 incidental appendectomies would be required to prevent one future instance of appendicitis and 4,472 incidental appendectomies would be needed to prevent a single future death from acute appendicitis. Because incidental appendectomy increases the risk for wound infection among persons undergoing cholecystectomy and because the lifetime risk for acute appendicitis is relatively low for persons of this age group, surgeons should carefully consider the risks and benefits of incidental appendectomy in the elderly.

The impact and cost of influenza in the elderly.

BACKGROUND: Traditional methods of measuring the impact and cost of influenza virus have focused on epidemic years and morbidity and mortality due to pneumonia and influenza. METHODS: Annualized age-sex-race adjusted rates of hospitalization for pneumonia and influenza and other diagnoses among elderly Medicare beneficiaries during the epidemic influenza season of 1989 to 1990 and the nonepidemic season of 1990 to 1991 were compared with an interim period in 1990 without influenza virus circulation. RESULTS: The rates of hospitalization for pneumonia and influenza, acute bronchitis, chronic respiratory disease, and congestive heart failure were significantly greater during each influenza period compared with the interim period. The highest rates were found in the epidemic season of 1989 to 1990. The amount reimbursed by Medicare to hospitals to 1990. The amount reimbursed by Medicare to hospitals for the treatment of excess hospitalizations during periods of influenza activity was more than $1 billion in 1989 to 1990 and almost $750 million in 1990 to 1991. CONCLUSIONS: Measures of the impact and cost of influenza in elderly Americans should include all of the diagnoses listed above and should recognize that the impact of influenza virus is significant even in nonepidemic years. There are great opportunities for cost savings if effective control programs are implemented.

Accuracy of coding in Medicare part B claims. Cataract as a case study.

We studied the accuracy of Medicare part B coding for cataract extraction to provide validation for research involving Medicare data. Hospital and physician office records associated with a sample of 802 paid claims for cataract surgery were reviewed. The sample was randomly selected from 118,420 Medicare part B claims for cataract surgery submitted by physicians in an 11-state sample during the first quarter of 1988. Medical records were successfully obtained for 796 cataract surgery episodes (99.2%), of which 794 (99.7%) indicated that cataract extraction had been performed. In the remaining two cases, cataract surgery was attempted but aborted. In 24 (3%) of the 794 cases, the surgical approach (intracapsular or extracapsular) indicated in the operative note differed from the coded on the physician's bill. In all cases in which the operative note indicated a secondary procedure performed at the time of surgery, the billing information was in agreement. We conclude that, at least in the case of cataract surgery, the Medicare part B database is 99% accurate (95% confidence interval, +/- 0.6%) for cataract surgery having occurred and 96% accurate (95% confidence interval, +/- 1.4%) in terms of surgical approach.

Determination of lung cancer incidence in the elderly using Medicare claims data.

The Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute provides data for making national estimates of lung cancer incidence and for monitoring secular trends. The authors compared the number of cases of lung cancer and the incidence rates among elderly residents of the five states included in the SEER program in 1986-1987 with the number of incident cases identified and the rates calculated using hospitalization and enrollment data on elderly Medicare beneficiaries maintained by the Health Care Financing Administration (HCFA) for the same years. The SEER program state registries identified 5.9% more cases than did HCFA (p < 0.01). However, the overall rates were similar (274.2/100,000 population for SEER and 264.7/100,000 population for HCFA), as were the majority of the rates for the different demographic subgroups examined. Age-adjusted lung cancer incidence rates for 1986 through 1990 among elderly Medicare beneficiaries residing outside of all nine SEER areas were 8-13 percent higher than the rates calculated for SEER-area residents. This observation is supported by the existence of similar differences in the age-adjusted lung cancer mortality rates for 1979 through 1988 in the same populations. Because the SEER areas may not be representative of the entire nation for lung cancer incidence and HCFA data cover the entire country, the authors recommend using HCFA information to complement the SEER data system.