Relation between hospital primary angioplasty volume and mortality for patients with acute MI treated with primary angioplasty vs thrombolytic therapy.

CONTEXT: Institutional experience with primary angioplasty has been suggested as a factor in selecting a reperfusion strategy for patients with acute myocardial infarction (AMI). However, no large studies have directly compared outcomes of primary angioplasty vs thrombolytic therapy as a function of institutional experience. OBJECTIVE: To compare outcomes among patients with AMI who were treated with primary angioplasty vs thrombolytic therapy at hospitals with different volumes of primary angioplasty. DESIGN: Retrospective cohort. SETTING: A total of 446 acute care hospitals with 112 classified as low volume (/=49 procedures) based on their annual primary angioplasty volume. PATIENTS: A total of 62 299 patients with AMI treated with primary angioplasty or thrombolytic therapy from June 1, 1994, through July 31, 1999. MAIN OUTCOME MEASURE: In-hospital mortality. RESULTS: Mortality was lower among patients who received primary angioplasty compared with those who received thrombolysis at hospitals with intermediate volumes (4.5% vs 5.9%; P<.001) and high volumes (3.4% vs 5.4%; P<.001) of primary angioplasty. At low-volume hospitals, there was no significant difference in mortality between patients treated with primary angioplasty vs those treated with thrombolysis (6.2% vs 5.9%; P =.58). Adjusting for differences in demographic, medical history, clinical presentation, treatment, and hospital characteristics did not significantly alter these findings. CONCLUSIONS: In this study, patients with AMI treated at hospitals with high or intermediate volumes of primary angioplasty had lower mortality with primary angioplasty than with thrombolysis, whereas patients with AMI treated at hospitals with low angioplasty volumes had similar mortality outcomes with primary angioplasty or thrombolysis.

Effect of a pediatric self-care book on utilization of services in a group model HMO.

The purpose of this study was to determine the effect of a pediatric self-care book (SCB) with nurse telephone support on use of health services. The study was performed in a pediatric department of Kaiser Permanente in a suburb of Denver, Colorado. Well patients seen at age 2 weeks to 2.5 months (infant group) or 14 to 19 months (toddler group) were enrolled. Intervention families received a copy of the book, Your Child's Health and were oriented on its use. Rates of sick visits, advice nurse calls, pharmacy prescriptions, emergency department visits, and hospital admissions were assessed. Visit and call rates were calculated, and mean rates of the SCB group and the control group were then compared. Of 1,104 enrols, 527 received the SCB; the other 577 served as controls. The SCB group had 14.0% fewer total visits (excluding well-baby visits) than controls did (p = 0.018). For infants and toddlers who were not first-borns, the intervention was associated with a statistically significant decrease in sick visits (23%), advice nurse phone calls (24%), and pharmacy prescriptions (26%); no statistically significant differences in study outcomes were seen among first-born study subjects. Promotion of self-care in a group model health maintenance organization can decrease use of services by families of young children.

Managed care and school-based health centers. Use of health services.

OBJECTIVE: To explore the use of physical and mental health services for adolescents who are enrolled in managed care and have access to a school-based health center (SBHC), compared with adolescents enrolled in managed care without access to an SBHC. DESIGN: Retrospective cohort designed with age, sex, and socioeconomic status matching to compare the use of health services for adolescent members of Kaiser Permanente of Colorado (who had access to SBHCs) with those with no access. PARTICIPANTS: The study included 342 adolescents, resulting in 3394 visits that occurred during 3 academic years. During the study, 240 adolescents with access to an SBHC were compared with 116 adolescents without access to an SBHC. MAIN OUTCOME MEASURES: The use of primary and subspecialty medical, mental health, and substance abuse treatment services; the use of after-hours (emergent or urgent) care; and comprehensive preventive health supervision visits and documentation of screening for high-risk health behaviors. RESULTS: Adolescents with access to SBHCs were more than 10 times more likely to make a mental health or substance abuse visit (98% of these visits were made at the SBHC) (P < .001). Adolescents with SBHC access had an after-hours (emergent or urgent) care visit rate of 0.33 to 0.52 visits per year less (38%-55% fewer visits) than adolescents without SBHC access, and, overall, made almost 1 additional medical visit per year. A greater percentage, 80.2%, of adolescents with access to SBHCs had at least 1 comprehensive health supervision visit compared with 68.8% of adolescents without access (P = .04). In addition, the adolescents with access were screened for high-risk behaviors at a higher rate. CONCLUSIONS: School-based health centers seem to have a synergistic effect for adolescents enrolled in managed care in providing comprehensive health supervision and primary health and mental health care and in reducing after-hours (emergent or urgent) visits. School-based health centers are particularly successful in improving access to and treatment for mental health problems and substance abuse.

Mortality from intentional and unintentional injury among infants of young mothers in Colorado, 1986 to 1992.

OBJECTIVES: To investigate the association between maternal age and other risk factors and infant injury deaths in the state of Colorado from 1986 to 1992. DESIGN: A retrospective cohort design was used to compare rates of unintentional and intentional infant injury mortality by maternal age group. A case-control design explored the importance of various risk factors, particularly maternal age, using multivariate logistic regression. PARTICIPANTS: The 2 case groups comprised all unintentional and intentional injury deaths in the first year of life. The control group was a random sample of both survivors and noninjury deaths selected from the entire birth cohort. RESULTS: The infant injury mortality rate for the 322766 live births in Colorado from 1986 to 1992 was 3.1 per 10000. Intentional injury death rates were highest for infants of teenaged mothers, peaking at 10.5 per 10000 live births for mothers aged 16 years. Unintentional injury death rates were highest for infants of mothers aged 20 to 24 years, peaking at 3.7 per 10000 live births for 22-year-old mothers. For intentional injury death, maternal marital status had a significant impact on maternal age; compared with the baseline group of married mothers older than 24 years, significantly higher risks were observed for infants of teenagers who were married (odds ratio [OR] = 32.0; 95% confidence interval[CI], 9.9-104.0) but also in infants of older mothers who were unmarried (OR = 3.6; 95% CI, 1.0-13.0 for unmarried mothers aged 20-24 years and (OR = 7.7; 95% CI, 2.4-25.0 for those > 24 years). Black race (OR = 3.5; 95% CI, 1.4-9.4) was also associated with intentional injury death. For unintentional injury death, the highest risk was for infants of mothers aged 20 to 24 years and unmarried (OR = 3.9; 95% CI, 1.7-9.3). Risk was also elevated for infants of married teenaged mothers (OR = 3.5; 95% CI, 0.7-17.8) but was not significantly different from the baseline group for unmarried teenagers, married 20- to 24-year-old mothers, or unmarried mothers aged 25 years or older. Risk was increased by the presence of older siblings (OR = 1.5 per sibling; 95% CI, 1.2-2.0). CONCLUSIONS: Maternal age and marital status significantly affect the rate of both unintentional and intentional infant injury mortality. These results suggest that child abuse prevention strategies should be targeted to teenaged mothers, and that strategies designed to prevent unintentional injuries should focus particularly on parents or caretakers of infants born to unmarried mothers in their early 20s as well as married teenagers.

Using a mailed survey to predict hospital admission among patients older than 80.

OBJECTIVE: To determine if the results of a questionnaire mailed to older patients can help identify those patients at greatest risk of hospital admission. DESIGN: A longitudinal cohort study. SETTING: A prepaid managed care plan in the Denver metropolitan area. PARTICIPANTS: Of the 4414 eligible patients at least 81 years old, 3745 (84.8%) responded. MEASUREMENTS: We studied the predictive power of self-reported demographic, health status, medical history, health habits, functional status (including Katz' activities of daily living and OARS instrumental activities of daily living), and socioeconomic status data to identify those older adults at greatest risk of hospitalization within 4.5 months of completing the survey. We derived our predictive model on one-half the subjects and tested its validity it on the other half. RESULTS: Univariate analysis revealed 25 variables significantly associated with hospital admission. In a logistic regression model, four significant variables successfully stratified the patients by risk of admission. These four variables are: the presence of heart disease, the presence of diabetes, need for help preparing meals, and limited physical independence (requiring the help of a person or mechanical aid to get around). In addition, there was an antagonistic interaction between the presence of heart disease and limited physical independence. The model stratified patients from low risk (4.5% chance of admission) to high risk (39% chance of admission). As measured by the Hosmer-Lemeshow statistic and the area under a receiver-operator characteristic (ROC) curve, this model fit both the derivation and validation subjects well. CONCLUSIONS: A mailed questionnaire achieved a high response rate, and the information collected produced an effective model predictive of hospitalization in the short term. Four easily ascertained pieces of information identify those patients older than age 81 at increased risk.

The danger of applying uniform clinical policies across populations: the case of breast cancer in American Indians.

OBJECTIVES: This study examined the implications of annual screening mammography for cost and mortality in American Indian populations with differing baseline breast cancer rates. METHODS: A decision tree compared annual screening mammography and screening clinical breast examination with referral for diagnostic mammography when appropriate. The decision tree was constructed to examine the effect of different base-line cancer rates, stage at diagnosis, and stage-specific survival. Outcomes included 5-year relative survival, deaths prevented at 5 years, cost per death prevented, and total costs. RESULTS: The findings suggest that the total cost of breast cancer is 3.6 times higher with the screening mammography program but results in a 27.9% reduction in breast cancer deaths over the first 5 years of the program. Both costs and deaths prevented are sensitive to the incidence of breast cancer in the population and are less favorable in the range of incidence seen in American Indians. CONCLUSIONS: The cost and impact of a given strategy for cancer screening vary among communities with different disease incidence, stage at diagnosis, and stage-specific survival, as seen in American Indian populations.

Chlamydia trachomatis antibody titers and hysterosalpingography in predicting tubal disease in infertility patients.

OBJECTIVE: To determine if the number of diagnostic laparoscopies done on women without tubal adhesive disease could be reduced by testing for tubal disease with Chlamydia trachomatis antibody titers and hysterosalpingography (HSG), either singly or together. DESIGN: Historical prospective chart review. SETTING: The Colorado Kaiser Permanente Reproductive Endocrinology Clinic. PATIENTS: All 703 infertility patients who had C. trachomatis antibody titers done from March 2, 1988 to April 30, 1992. The final study group was comprised of 218 patients who had antibody titers, HSG, and laparoscopy. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Sensitivity, negative predictive value, and false-positive rate were the test characteristics of interest. Tubal disease was identified by laparoscopy. RESULTS: For HSG testing, the sensitivity was 78% and the negative predictive value was 85%. For C. trachomatis titers, the sensitivity was also 78% and the negative predictive value was 82%. Ninety-five percent confidence intervals for sensitivity and negative predictive value overlapped, indicating that there was no significant difference. However, false-negative rates were the same for the two tests, but false-positive rates were lowest for HSG and series testing. CONCLUSIONS: To minimize false-positive tests and thus, to minimize unnecessary laparoscopies, HSG testing either alone or combined with the C. trachomatis antibody titer as series tests yielded a significantly lower false-positive rate. In our study group, if both tests were negative, tubal disease was identified on laparoscopy in only 5% of cases. Choice of most cost-effective test sequence will depend on who bears the cost. Further studies of cost-benefit using well-defined testing sequences are needed to determine if C. trachomatis antibody titers in series with HSG would be more cost effective than HSG alone in detecting tubal disease.

Appropriateness of hospital use by family physicians.

BACKGROUND: Reducing inappropriate hospital admissions could lead to lower total health care costs without compromising the quality of care. Research suggests that a sizeable portion of hospital admissions are inappropriate. Other studies indicate that family physicians use health care resources, including hospitalizations, less often than other primary care physicians. To gain additional insight into family physicians' decisions to admit patients, we performed an exploratory study using the Appropriateness Evaluation Protocol, a validated, clinically based utilization review instrument. METHODS: We assessed admissions by community-based and residency-based family physicians to a single university-affiliated hospital during calendar year 1988. A total of 905 patients were admitted to the hospital by family physicians during the study period. Of these, 889 records had complete data. Each was reviewed for appropriateness of admission. We calculated percentages of inappropriate admissions and used logistic regression to ascertain variables that were significant predictors of inappropriateness. RESULTS: Overall, 5.4 percent of admissions were categorized as inappropriate. Omitting obstetric cases, the rate was 10.5 percent. Inappropriate admissions did not cluster around a small number of diagnoses or diagnosis-related groups. Using logistic regression, we found that urgency of admission, patient insurance status, and residency-based physician admission versus community-based physician admission were significant predictors of inappropriate hospital use. Of the inappropriate admissions, 70 percent were so rated because diagnostic procedures or treatments could have been performed on an outpatient basis. CONCLUSIONS: In contrast with other studies for which physician specialty was not controlled, family physicians less frequently admitted patients inappropriately. Predictors of inappropriateness differed from those found in other studies. Changes in hospital systems, in addition to educational efforts directed toward individual physicians, hold promise as a strategy for reducing inappropriate hospital use.

Factors influencing mammogram ordering at the time of the office visit.

BACKGROUND: Breast cancer is the second most common cause of cancer death in women, with mammographic screening the only modality shown to decrease the death rate. However, only 17% to 41% of women have ever been screened, and multiple barriers to screening have been identified. This study examined physician and patient factors at a single encounter to explore components influencing mammography ordering. METHODS: Ten family physicians in a primary care research network completed daily data cards on encounters with women presenting for annual examinations, chronic problems, or breast-related complaints. Information collected included patient age, personal or family history of breast cancer, physician's perception of expected compliance, previous mammogram results, breast examination, physician's perception of need for a mammogram, whether the mammogram was ordered, and the patient's method of payment for the test. RESULTS: Eight hundred thirty-nine patients were entered into the study, and 277 mammograms were ordered. Mammograms were ordered for a greater percentage of patients with insurance (36%) than for those without insurance (26%) (P < .001). A multivariate analysis indicated that several factors helped to correctly classify 90% of mammogram ordering: the patient was making a first visit, a breast-related visit, or a visit for an annual examination; the patient had had a previous mammogram; had a breast examination at the current visit or within the past year; and the physician believed the patient would comply and believed that a mammogram was indicated. CONCLUSIONS: Factors unique to a physician-patient visit influence the physician with regard to ordering a mammogram, including the type of visit, whether the physician believes a mammogram is indicated, and the cost.

Association between clinical experiences in family practice or in primary care and the percentage of graduates entering family practice residencies.

In 1990 the authors surveyed all U.S. medical schools in order to solicit information about students' clinical experiences in family practice and in primary care. Of 126 schools, 104 (82.5%) responded. Survey data were correlated with each school's quartile ranking based on the average percentage of graduates who entered family practice residencies. A significant association (p = .0013) was found between required family practice clerkships or preceptorships and institutions ranked in the highest quartile (i.e., having more than 17% of their graduates enter family practice). A similarly significant association (p = .0056) was found for those 12 institutions that had more than 30% of their students select family practice options in required primary care clerkships or preceptorships. The authors suggest that active recruiting of students to take such options may increase the number of graduates who enter family practice.

AIDS in primary care: a report from the Ambulatory Sentinel Practice Network.

BACKGROUND: Despite the importance of the epidemic of acquired immune deficiency syndrome (AIDS), little is known about the incidence and prevalence of AIDS in the patient population of primary care physicians. This study was designed as an initial step in evaluating the impact of this disease on primary care practices. METHODS: We conducted a survey to characterize the AIDS cases in the Ambulatory Sentinel Practice Network (ASPN). ASPN is a practice-based primary care research network. In 1987 it was composed of 65 practices and 193 clinicians serving approximately 270,000 patients in the United States and Canada. Clinicians representing each practice were asked to report the number of AIDS patients that their practice cared for between January 1982 and December 1987. They were further asked to characterize relevant data for these patients. RESULTS: Thirty-nine prevalent cases of AIDS were reported in ASPN from January 1982 through December 1987. Seventy-nine percent of the patients were male, 15 to 44 years of age; three patients (7.6%) were female; and all cases had at least one risk factor for AIDS. An expected number of cases for the 194,973 patients of 47 practices was calculated using age-sex register data and nationally based rates from 1986. The projected number, 13, corresponded with the number of AIDS cases, 11 and 15, reported from ASPN practices in 1986 and 1987, respectively. CONCLUSIONS: This survey suggests that AIDS is at least as prevalent in the primary care practices in ASPN as predicted using national estimates, and may, in fact, be more prevalent. Primary care clinicians need to be prepared to assume a major role in addressing the AIDS epidemic.

The development and management of a primary care research network, 1978-87.

The Ambulatory Sentinel Practice Network (ASPN) was created to increase the knowledge of primary care. Building on the experiences of other national and regional primary care research networks, ASPN has evolved as a North American network including practices in 25 U.S. states and four Canadian provinces in 1987. This paper summarizes ASPN's growth and development since 1978, the involvement of the ASPN practices, and the mechanisms used in developing and managing studies.

Age/sex registries in primary care research.

Age/sex registries have been examined as a method of estimating the number of individuals served by a primary care practice. These data can be used in estimating disease frequency from primary care encounter data. The experience with age/sex registries in the Ambulatory Sentinel Practice Network (ASPN) has identified three major sources of error when registry data are used to estimate disease rates: (1) studies using medical encounter data exclude those individuals who do not seek medical care, (2) visitation is not random and is a function of variables in addition to disease incidence, and (3) encounter data from primary care practices are incomplete due to reporting problems and patient-initiated visits to other health care providers. Despite these limitations, age/sex registries can provide a practical tool for estimating disease rates in appropriate settings, assessing the generalizability of results, and assessing the feasibility of studies in practice based research. Further research about age/sex registries is needed to improve disease rate estimation as well as to better define methods. An age/sex registry enumerates a population by age and sex categories. Such a registry of the patients cared for by a medical practice represents a useful tool for practice based research. This paper briefly reviews the background of age/sex registries in North America, describes the experience of the Ambulatory Sentinel Practice Network with age/sex registries, identifies problems in using age/sex registries to provide denominator data for disease frequency estimation, and explores other uses for age/sex registry data.