Developing a quality improvement database using health insurance data: a guided tour with application to Medicare's National Claims History file

Use of gonioscopy in medicare beneficiaries before glaucoma surgery

PURPOSE

The American Academy of Ophthalmology Preferred Practice Patterns for angle closure and open-angle glaucoma (OAG) patients recommends performing bilateral gonioscopy upon initial presentation to evaluate the possibility of narrow angle or angle-closure glaucoma (ACG) and then repeating the examination at least every 5 years. This study aims to assess how commonly eye care providers perform gonioscopy before planned glaucoma surgery in OAG, anatomic narrow angle, and ACG in the Medicare population.

METHODS

Data obtained from a 5% random sample of Medicare beneficiaries undergoing glaucoma surgery in the United States in 1999 were retrospectively reviewed. The proportion of patients with evidence of at least one gonioscopic examination before glaucoma surgery was determined for the period of 1995 to 1999. Demographic and clinical factors potentially influencing the decision to perform gonioscopy were also examined.

RESULTS

Overall, gonioscopy is apparently performed in 49% of Medicare beneficiaries during the 4 to 5 years preceding glaucoma surgery. This rate was significantly lower (P < 0.001) in patients with OAG (46%), as compared with anatomic narrow angle (58%) and ACG (57%) patients. Hispanics, elderly (aged 70 to 84), patients undergoing laser iridotomy, and patients receiving care in the New York/New Jersey area all had significantly higher apparent preoperative gonioscopy rates (P < 0.05).

CONCLUSIONS

Gonioscopy examination before glaucoma surgery in Medicare beneficiaries is underused, undercoded, and/or miscoded, given current recommendations. Underuse is of particular concern in patients undergoing laser iridotomy as it is the diagnostic test of choice in ACG.

Lessons Learned from Performance Feedback by a Quality Improvement Organization

Performance feedback is a common quality improvement (QI) intervention strategy in the outpatient setting. This article describes the use by one quality improvement organization (QIO) of performance feedback to primary-care physicians with claims-based measures relating to diabetes, adult vaccinations, and mammography screening. Feedback from the physicians identified themes relating to data accuracy, methodology of the feedback reports, reasons for low performance rates, and suggestions on how the QIO could improve its intervention strategy. The article highlights the value of collecting and analyzing formative data on the process and offers specific recommendations to other QI professionals contemplating the use of claims data for performance feedback.

Visual field testing in glaucoma Medicare beneficiaries before surgery

OBJECTIVE

The standard of care for progressive glaucoma that requires medical or surgical intervention includes visual field (VF) testing at least annually. This study aims to assess how commonly ophthalmologists perform VF testing before planned glaucoma surgery in the Medicare population, and whether variations in conformance occur across demographic and clinical subgroups.

DESIGN

Retrospective, observational, population-based analysis.

PARTICIPANTS

Thirteen thousand seven hundred fifty-three Medicare beneficiaries.

METHODS

Data were obtained from a 5% random sample of Medicare beneficiaries undergoing glaucoma surgery in the United States from 1995 to 1999. The proportion of patients with evidence of at least 1 VF examination in the year before glaucoma surgery was determined.

MAIN OUTCOME MEASURE

Rate of VF testing in the year before glaucoma surgery.

RESULTS

Overall, 70% of patients had at least 1 VF test in the year preceding glaucoma surgery. This rate was significantly lower (P<0.001) in patients > or =85 years (56%), blacks (64%), patients with race other than white or black (66%), patients with diabetic retinopathy (60%), and patients with bilateral blindness (47%).

CONCLUSIONS

The use of VF testing before surgery in glaucoma Medicare beneficiaries is suboptimal relative to the recommended standard of care. Underutilization is of particular concern in blacks, who are at increased risk of glaucomatous damage. Quality-of-care initiatives are needed to facilitate appropriate preoperative evaluations of glaucoma Medicare beneficiaries for glaucoma surgery.

Validation of diagnostic codes within medical services claims

OBJECTIVES

Few studies have attempted to validate the diagnostic information contained within medical service claims data, and only a small proportion of these have attempted to do so using the medical chart as a gold standard. The goal of this study is to determine the sensitivity and specificity of medical services claims diagnoses for surveillance of 14 drug disease contraindications used in drug utilization review, the Charlson comorbidity index and the Johns Hopkins Adjusted Care Group Case-Mix profile (ADGs).

STUDY DESIGN AND SETTING

Diagnoses were abstracted from the medical charts of 14,980 patients, and were used as the "gold standard," against which diagnoses obtained from the administrative database for the same patients were compared.

RESULTS

Conditions associated with drug disease contraindications with the exception of hypertension and chronic obstructive pulmonary disease (COPD) showed a specificity of 90% or higher. Sensitivity of claims data was substantially lower, with glaucoma, hypertension, and diabetes being the most sensitive conditions at 76, 69, and 64%, respectively. Each of the 18 disease conditions contained in the Charlson comorbidity index showed high specificity, but sensitivity was more variable among conditions as well as by coding definitions. Although ADG specificity was also high, the vast majority of ADGs had sensitivities of less than 60%.

CONCLUSION

The administrative data was found to have diagnoses and conditions that were highly specific but that vary greatly by condition in terms of sensitivity. To appropriately obtain diagnostic profiles, it is recommended that data pertaining to all physician billings be used.

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.

Hip fracture incidence in nursing home residents and community-dwelling older people, Washington State, 1993-1995

OBJECTIVES

To establish and validate a method of linking data from the Minimum Data Set (MDS) and Medicare hospital claims, to estimate hip fracture incidence rates for Medicare beneficiaries aged 65 and older in Washington State, and to compare the incidence rates of hip fractures in nursing home and non-nursing home residents.

DESIGN

Retrospective analysis of Medicare population-based enrollment, hospital claims, and nursing home administrative data sets.

SETTING

Nursing home and non-nursing home setting.

PARTICIPANTS

Medicare beneficiaries in Washington State residing in the community or in skilled nursing facilities.

MEASUREMENTS

Crude age- and sex-specific and standardized age- and sex-adjusted hip fracture incidence for persons residing and not residing in nursing homes.

RESULTS

From October 1, 1993, through September 30, 1995, 7,812 Medicare beneficiaries aged 65 or older were hospitalized for hip fractures (6,566 fractures for 1,155,234 person-years of exposure in non-nursing home residents and 1,246 fractures for 42,986 person-years of exposure in nursing home residents). The standardized age- and sex-adjusted hip fracture rate of nursing home residents (23.0 per 1,000 person-years) substantially exceeded that of non-nursing home residents (5.7 per 1,000 person-years) (incidence rate ratio = 4.0, 95% confidence interval = 3.7-4.5).

CONCLUSION

The incidence of hip fracture in nursing home residents far exceeds that in noninstitutionalized older people. Linkage of MDS and Medicare hospital claims data is a useful tool for epidemiological surveillance regarding events in nursing homes that are likely to result in hospitalization.

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.

The use of Medicaid claims as a supplementary source of information on quality of asthma care

This study examines the correspondence between medical records and Medicaid claims to determine whether claims are a valid source of data for monitoring quality of asthma care. A total of 460 claims for care encounters were matched to medical records of the encounters. While most of the diagnoses and procedures recorded on the claims were documented in medical records, claims failed to identify 29% of encounters with asthma diagnoses and 45% of nebulization procedures administered during encounters. About 30% of documented asthma prescriptions were not associated with filed claims, and about 30% of filed claims for asthma medication were not documented in medical records.

The diffusion of information technology among health maintenance organizations

This article examines the information technology functions, staffing and cost, services provided, and advanced technologies among health maintenance organizations (HMOs) using a national sample of HMOs from mid-1995. HMOs have a well-developed capability to use data from administrative functions, such as claims processing. Nationally affiliated HMOs and HMOs in markets with greater HMO penetration support more IT functions. Relatively little work has been completed integrating clinical with administrative systems.

Differences between generalists and specialists in characteristics of patients receiving gastrointestinal procedures

BACKGROUND

As a result of market forces and maturing technology, generalists are currently providing services, such as colonoscopy, that in the past were deemed the realm of specialists.

OBJECTIVE

To determine whether there were differences in patient characteristics, procedure complexity, and clinical indications when gastrointestinal endoscopic procedures were provided by generalists versus specialists.

DESIGN

Retrospective cohort study.

PATIENTS

A random 5% sample of aged Medicare beneficiaries who underwent rigid and flexible sigmoidoscopy, colonoscopy, and esophagogastroduodenoscopy (EGD) performed by specialists (gastroenterologists, general surgeons, and colorectal surgeons) or generalists (general practitioners, family practitioners, and general internists).

MEASUREMENTS

Characteristics of patients, indications for the procedure, procedural complexity, and place of service were compared between generalists and specialists using descriptive statistics and logistic regression.

MAIN RESULTS

Our sample population had 167,347 gastrointestinal endoscopies. Generalists performed 7.7% of the 57, 221 colonoscopies, 8.7% of the 62,469 EGDs, 42.7% of the 38,261 flexible sigmoidoscopies, and 35.2% of the 9,396 rigid sigmoidoscopies. Age and gender of patients were similar between generalists and specialists, but white patients were more likely to receive complex endoscopy from specialists. After adjusting for patient differences in age, race, and gender, generalists were more likely to have provided a simple diagnostic procedure (odds ratio [OR] 4.2; 95% confidence interval [95% CI] 4.0, 4.4), perform the procedure for examination and screening purposes (OR 4.9; 95% CI, 4. 3 to 5.6), and provide these procedures in rural areas (OR 1.5; 95% CI 1.4 to 1.6).

CONCLUSIONS

Although generalists perform the full spectrum of gastrointestinal endoscopies, their procedures are often of lower complexity and less likely to have been performed for investigating severe morbidities.

The effect of the doctor-patient relationship on emergency department use among the elderly

OBJECTIVES

This study sought to determine the rate of emergency department use among the elderly and examined whether that use is reduced if the patient has a principal-care physician.

METHODS

The Health Care Financing Administration's National Claims History File was used to study emergency department use by Medicare patients older than 65 years in Washington State during 1994.

RESULTS

A total of 18.1% of patients had 1 or more emergency department visits during the study year; the rate increased with age and illness severity. Patients with principal-care physicians were much less likely to use the emergency department for every category of disease severity. After case mix, Medicaid eligibility, and rural/urban residence were controlled for, the odds ratio for having any emergency department visit was 0.47 for patients with a generalist principal-care physician and 0.58 for patients with a specialist principal-care physician.

CONCLUSIONS

The rate of emergency department use among the elderly is substantial, and most visits are for serious medical problems. The presence of a continuous relationship with a physician--regardless of specialty--may reduce emergency department use.

Combining state administrative databases and provider records to assess the quality of care for children enrolled in Medicaid

Our objective was to assess the capability of state administrative health care databases to evaluate the quality of immunization rates for a Medicaid managed care population. Data on 5599 2 year olds were obtained from a Medicaid claims database, a health department database, and the records of the children's assigned providers. The study was conducted on 1 managed care program in 1 state. Test performance ratio analyses were used to assess the relative accuracy and contribution of each source of administrative data. We found that of the 67,188 doses needed, 45,511 (68%) were documented as administered per at least 1 of the data sources. Medicaid claims data alone accounted for 18% of immunized children, while health department data used by itself accounted for 12%. Together, these 2 sources identified 34% of immunized children. Large administrative databases, such as Medicaid claims and data from a health department, while valuable sources of information on quality, may underestimate outcomes such as immunization rates. Assessments of the quality of health care should rely on a combination of administrative data and providers' records as sources of information.

How valid are medical records and patient questionnaires for physician profiling and health services research? A comparison with direct observation of patients visits

OBJECTIVES

This study was designed to determine the optimal nonobservational method of measuring the delivery of outpatient medical services.

METHODS

As part of a multimethod study of the content of primary care practice, research nurses directly observed consecutive patient visits to 138 practicing family physicians. Data on services delivered were collected using a direct observation checklist, medical record review, and patient exit questionnaires. For each medical service, the sensitivity, specificity, and Kappa statistic were calculated for medical record review and patient exit questionnaires compared with direct observation. Interrater reliability among eight research nurses was calculated using the Kappa statistic for a separate sample of videotaped visits and medical records.

RESULTS

Visits by 4,454 patients were observed. Exit questionnaires were returned by 74% of patients. Research nurse interrater reliabilities were generally high. The specificity of both the medical record and the patient exit questionnaire was high for most services. The sensitivity of the medical record was low for measuring health habit counseling and moderate for physical examination, laboratory testing, and immunization. The patient exit questionnaire showed moderate to high sensitivity for health habit counseling and immunization and variable sensitivity for physical examination and laboratory services.

CONCLUSIONS

The validity of the medical record and patient questionnaire for measuring delivery of different health services varied with the service. This report can be used to choose the optimal nonobservational method of measuring the delivery of specific ambulatory medical services for research and physician profiling and to interpret existing health services research studies using these common measures.

House calls to the elderly--a vanishing practice among physicians

BACKGROUND

Despite the growth in other home health care services, the number of house calls by physicians has declined dramatically during this century. We determined the frequency of house calls made by physicians to elderly U.S. patients in 1993 and analyzed the characteristics of the physicians and patients involved.

METHODS

We analyzed a 5 percent random sample of the 1993 Medicare Part B claims data for beneficiaries over the age of 65 who were not enrolled in health maintenance organizations (HMOs). With supplemental information from the Area Resource File and the American Medical Association's Physician Masterfile, we determined how many house calls were made, their cost, and a number of specific characteristics of the physicians and the patients.

RESULTS

In our 1993 sample, 36,350 house calls were made to 11,917 of the 1,357,262 patients. When extrapolated to all Medicare beneficiaries over age 65 and not enrolled in HMOs, these figures correspond to 727,000 house calls to 238,340 patients nationwide. We estimated the cost of these house calls to be $63 million. The patients who received house calls from physicians were older than those who did not, were more likely to die within the calendar year, had higher rates of hospitalization, and were more likely to receive care from other home health providers, hospice programs, and skilled-nursing facilities. Patients residing in rural areas and those in areas with high physician-to-population ratios had an increased likelihood of receiving a house call. The physicians who made house calls were more likely than others to be generalists, osteopaths, older, male, board-certified, practicing in the Northeast, and in solo practice.

CONCLUSIONS

A very small percentage (0.88 percent) of elderly Medicare patients, mainly those who are very sick and near the end of life, receive house calls from physicians.