The utilization of pneumococcal polysaccharide vaccine among elderly Medicare beneficiaries, 1985 through 1988.

Since July 1981, Medicare has paid for the administration of pneumococcal vaccine without regard to the deductible limit and without copayment. Claims submitted to Medicare for reimbursement for the 4-year period from 1985 through 1988 for a 5% sample of elderly Medicare beneficiaries enrolled in part B who were not members of health maintenance organizations were analyzed. Vaccine was administered to an estimated 1,392,840 beneficiaries (5.34%). The total estimated cost to Medicare was $14.3 million, or approximately $10.27 per dose. Crude 4-year rates indicated that white persons were much more likely to be immunized than black persons (5.60% vs 2.94%). Persons 70 through 84 years of age had higher immunization rates than either younger or older beneficiaries. The number of immunizations given peaked in 1986 and declined thereafter. A variety of vaccination strategies that may raise the immunization level in the elderly have been developed. The broad implementation of successful strategies will be important if the goal of a 60% immunization level in the elderly by the year 2000 is to be reached.

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.

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.

Physician knowledge, attitudes, and behavior related to reporting adverse drug events.

Voluntary physician reporting of adverse drug events (ADEs) in their patients remains the single most important source of information on serious and rare ADEs. Yet, substantial underreporting exists and the factors producing it are unclear. We surveyed 3000 randomly chosen physicians by mailed questionnaire to determine their knowledge about the reporting system, attitudes toward reporting, and their past behavior in reporting the ADEs they had detected. Responses numbered 1121. Only 57% were aware of the Food and Drug Administration's reporting system. While 418 physicians had detected an ADE in their practices during the previous year, only 21 physicians reported these events directly to the Food and Drug Administration. The physicians appear to appreciate the safety issues involved in prescription drug use and view reporting as a professional obligation; however, the current reporting system is considered inconvenient.

Simultaneous administration of live attenuated measles vaccine with DTP vaccine.

Live attenuated measles vaccine was administered to Cameroonian children 12 to 39 months of age alone or with either diphtheria-tetanus toxoids or diphtheria and tetanus toxoids and pertussis (DTP) vaccine. Among children who were initially seronegative for measles hemagglutination inhibition antibodies, seroconversion rates and postvaccination geometric mean titers were similar in all groups. Pertussis antigen in the DTP vaccine was judged to be potent by laboratory potency testing and serologic response in recipients of the vaccine. Thus, the two vaccines may be administered simultaneously without compromising their immunogenicity. These results allow greater flexibility in planning individual or mass immunization schedules.

Rationale for the sequential use of inactivated poliovirus vaccine and live attenuated poliovirus vaccine for routine poliomyelitis immunization in the United States.

Despite the concerns mentioned in the last section, there are many reasons to believe that a polio immunization schedule that incorporates sequential doses of inactivated poliovirus vaccine and live attenuated poliovirus vaccine would provide both humoral and intestinal immunity to the fully immunized person that is at least as good, if not better, than the immunity achieved by the use of IPV or OPV alone. A substantial degree of protection should also extend to partially immunized and unimmunized preschool aged children in the community. Furthermore most of the cases of OPV-associated paralytic poliomyelitis could be prevented. Because the reasons for these beliefs are based on data from small studies and on inferences from related research, specific recommendations for a change from current polio immunization policy must depend on additional clinical research. Well-designed trials comparing several different options for sequencing both inactivated and live vaccines are needed, and these studies should focus carefully on both humoral and intestinal immunity conferred by the various vaccine schedules.

The epidemiology and control of measles in Yaoundé, Cameroun, 1968-1975.

Surveillance data on measles in Yaoundé during the 8 years from 1968-1975 have been reviewed. Measles epidemics occurred in every year except 1969-1970, the period of the attach phase of the Smallpox Eradication and Measles Control Programme. Subsequent biennial mass measles immunisation campaigns and maintenance measles immunisation at the child health centre failed to interrupt epidemic transmission. 70-80% of cases were under 24 months of age. Annual outbreaks occurred during the first half of each year, but smaller numbers of cases continued throughout the year. The outbreaks came to an end despite 32-41% of 6 through 36 month old children remaining susceptible. The seasonality of measles was not simply related to the annual rainfall pattern. Rather it is hypothesised that measles seasonality depends on the movement of young children with their mothers during the annual agricultural cycles. Measles immunisation programmes must be adapted to local epidemiological and cultural conditions in order to interrupt transmission.

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.

National outcomes of cataract extraction. III. Corneal edema and transplant following inpatient surgery.

We analyzed the likelihood of rehospitalization for corneal edema or corneal transplantation in all 338,141 Medicare beneficiaries older than 65 years who were admitted to US hospitals for cataract extraction in 1984. The rate of rehospitalization for corneal edema or transplant within 4 years of intracapsular cataract extraction was 1.4%, almost twice the rate associated with extracapsular extraction (0.63%) or phacoemulsification (0.62%; P less than .0001). No significant difference in the rate of corneal transplantation was detected between those undergoing extracapsular cataract extraction and those undergoing phacoemulsification. Among patients who had intracapsular cataract extraction, those who underwent concurrent intraocular lens implantation surgery had a higher rate of rehospitalization for corneal edema or transplantation than those who did not (1.11% vs 0.86%; P = .0003). However, this difference is only manifest starting at about 3 years after surgery. Among patients who underwent extracapsular cataract extraction and phacoemulsification, however, those who underwent intraocular lens implantation during surgery had a lower rate of corneal edema or transplantation than those who did not (0.47% vs 0.74%; P less than .0001). This difference was seen almost immediately after surgery. Cataract surgery accompanied by anterior vitrectomy was associated with a threefold increase in the 4-year rate of corneal edema or transplantation compared with cataract surgery alone (2.42% vs 0.87%; P less than .0001).

National outcomes of cataract extraction. Endophthalmitis following inpatient surgery.

We analyzed the likelihood of rehospitalization for endophthalmitis in 338,141 Medicare beneficiaries over age 65 years who were admitted to US hospitals for cataract extraction in 1984. This cohort represents approximately one half of all persons who underwent cataract extraction under the Medicare program in 1984. Extracapsular extraction was performed in 195,587 (58%) of cases, intracapsular cataract extraction in 99,971 (30%), and phacoemulsification in 28,474 (8%). The risk of rehospitalization for endophthalmitis in the year following surgery was 0.17% for intracapsular cataract extraction compared with 0.12% for extracapsular extraction or phacoemulsification (P less than .002). The risk of endophthalmitis at 1 month was higher for intracapsular cataract extraction than for extracapsular extraction or phacoemulsification (0.11% vs 0.085%), although the difference did not reach statistical significance. Cataract surgery accompanied by anterior vitrectomy increased the 1-month risk of rehospitalization for endophthalmitis to 0.41%, more than a four-fold increase over that for cataract surgery alone (0.09%; P less than .05). The rates of endophthalmitis at 1 year were 0.58% and 0.13%, respectively, for cataract surgery with anterior vitrectomy and cataract surgery alone (P less than .0001). No significant differences in the rate of rehospitalization for endophthalmitis were observed based on the use of an intraocular lens, age, or race. Endophthalmitis within 1 year of surgery was 1.2 times more frequent in men than in women (0.16% vs 0.13%; P = .03). Overall, the likelihood of postoperative endophthalmitis from a national sample is consistent with case series previously reported.

Evaluation of a mass measles immunization campaign in Yaoundé, Cameroun.

A mass measles immunization campaign carried out in Yaoundé, Cameroun, has been evaluated. Sixty per cent of the children were immune to measles at the time of the campaign. Only 51% of the susceptible children received vaccine. This was caused by a lack of attendance at the vaccination centres and errors in the selection of children given vaccine. The vaccine administered was relatively ineffective: 40% seroconversion. Difficulties which probably contributed to the low seroconversion rate included sub-optimal vaccine titre, inadequate doses of vaccine, and the relatively long time of vaccine utilization under tropical temperatures. Overall, 83% of the vaccine given to the vaccinating team was wasted. Future immunization campaigns can be improved through better screening of the children, improved handling of the vaccine, the use of marker vaccines, and improved health education.

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.

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.

Trends and patterns in place of death for Medicare enrollees.

Two changes in the Medicare program in 1983 may have affected where aged persons die--the change from retrospective hospital reimbursement to the prospective payment system and passage of the Medicare hospice benefit. Patterns and trends in where people die--hospitals, other institutions such as nursing homes, decedents' homes, and other places--for persons 65 years of age or over from 1980 through 1986 are examined. The proportion of deaths in hospitals declined somewhat after implementation of prospective payment. The hospice benefit may have caused the shift among cancer patients away from hospital deaths toward deaths at home.

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.

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 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.

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.

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.

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.