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.

Verification of data reported by practices for a study of spontaneous abortion.

Little is known about the accuracy of data reported in practice based primary care research. The Ambulatory Sentinel Practice Network (ASPN) undertook a 100% audit of 226 patients included in a study of spontaneous abortion (SAB). The audit was conducted to assess the feasibility of conducting audits in primary care research networks dispersed over large geographic areas, verify that patients met inclusion criteria, and assess the frequency of reporting errors using the medical record as a standard. Of the originally reported SABs, 24% could not be verified. The overall error rate was 4.5%, a total of 106 errors out of a possible 2,361. Seventy percent of these errors came from five of the 34 participating practices. Sixty-six percent of the records were error-free. Seventy-seven percent of the errors were associated with problems with methods and clustered into three categories: gravidity, gestational age, and dilation and curettage (D&C). According to this audit, the data reported by the practices for research purposes were very similar to the data found in the medical record.

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.

Using qualitative methods to evaluate health service delivery in three rural Colorado communities.

Qualitative and quantitative methods can be used simultaneously for hypothesis generation and testing. A pilot study was conducted in 1991 in three rural Colorado communities to clarify health service delivery problems related to cancer. The analysis focused on the perceptions of three types of respondents in each community related to whether cancer was a major problem, whether health services were adequate in their community, and what perceived solutions could be implemented. Respondents included community influentials, health care providers, and cancer patients or family members. Semistructured phone interviews were used to collect perceptions of these community members. Transcripts from the three communities were combined, coded, and tallied. Several distinct themes emerged from the analysis. These included: cancer was a major problem; public and provider education was needed; community systems and support to identify and solve health problems were lacking; medical networking needed to be expanded; transportation was a problem for remote communities; inability to pay for services was a problem for rural communities. Most respondents identified the problems as relevant to other chronic and acute diseases as well as cancer. This method identified the critical problems for the majority of the people without losing sight of the outlier responses.

Pediatric training in family practice: a core curriculum.

Official residency guidelines for pediatric training of family practice residents focus on the number of months of block time on pediatric rotations and the percentage of pediatric patients in the resident's model practice. These guidelines do not ensure competence in pediatrics. Family practice residencies need a competency-based curriculum derived from actual pediatric experience in family practice. Such a curriculum should define specific knowledge, skills, and attitudes required, define the family physician's role in handling each issue or condition, be used on a daily basis, and form a basis for evaluation of residents and curriculum. This paper describes the development and implementation of such a pediatric core curriculum at the University of Colorado Family Practice Residency.

Patients with new headache in primary care: a report from ASPN.

From a consecutive series of 3,847 headache patients, 1,331 patients who made first visits for new headache to 120 primary care physicians were studied for usual care over a 14-month period. Either tension or vascular headache was the initial diagnosis in 23.8 percent and 12.8 percent of patients, respectively. Nearly one half (47.8 percent) were classified as having headaches other than tension or vascular. A total of 15.3 percent of headaches were undiagnosed or were regarded as a mixture of traditional diagnostic designations. At first visit, most patients (76.6 percent) were managed without diagnostic tests. Drugs were prescribed for 73.6 percent, and advice was given for 58.6 percent. Only 2.0 percent of patients had computerized tomographic scanning ordered at first visit, although at least 46 percent met National Institutes of Health criteria, a finding with potential economic consequences of at least $2 billion. These findings suggest the need for reevaluation of diagnostic categories for headache, reevaluation of strategies for headache management, and further investigations of headache in primary care patients.

Differences in morbidity patterns among rural, urban, and teaching family practices: a one-year study of twelve Colorado family practices.

An analysis of one year's data from family practices in Colorado tested the hypothesis that there are no significant differences in the proportion of patients with problems in each of the 18 major International Classification of Health Problems in Primary Care (ICHPPC) categories among visiting patients in rural, urban, and teaching family practices. Four rural, three urban, and five residency practices participated in the study from January 1, 1978, through December 31, 1978. Transient patients were excluded. There were 25,525 patients included in the study. Each setting was compared with the other two settings in each of the 18 ICHPPC categories. More than half of the comparisons differed at the .001 significance level, and the setting with a significantly greater proportion of visiting patients with diseases in a given category was identified. These differences may have implications for disease surveillance, the planning for delivery of primary health care in different settings, and the preparation of health care providers for practice.

The usefulness of matched pair randomization for medical practice-based research.

To be feasible, study designs for most intervention research in primary care settings must limit the number of participating physicians, without sacrificing the statistical power required to test the research hypotheses. A model was developed to examine sample size and statistical power requirements when using the physicians' practice as the unit of analysis. Randomized designs using either matched or unmatched samples of practices were compared under varying conditions. When baseline variability is small or the number of practice pairs is large, matching at best marginally increases power. However, in the typical case when baseline variability is large or the number of practice pairs is small, matching substantially increases the power to find intervention effects with a smaller sample. Thus, matching prior to randomization could improve the design of many intervention studies in primary care settings.

How representative of typical practice are practice-based research networks? A report from the Ambulatory Sentinel Practice Network Inc (ASPN)

OBJECTIVE: To evaluate the patients and practices of family physicians in a national practice-based research network to understand whether results from practice-based research networks are likely to be relevant to other practicing clinicians. STUDY DESIGN: Survey focused on family physicians that replicated the National Ambulatory Medical Care Survey (NAMCS). SETTING: The Ambulatory Sentinel Practice Network Inc (ASPN), a practice-based research network, consisting of volunteer primary care practices that serve approximately 350,000 patients. OUTCOME MEASURES: Comparison of visits reported in ASPN with the visits reported in the 1990 NAMCS in terms of patient demographics, reasons for visit, diagnostic and therapeutic services, diagnoses, disposition, and amount of time spent with patients. RESULTS: Overall, the two samples differed with respect to demographic characteristics of patients, while problems, diagnoses, services, disposition, and time spent with patients were similar. Specific pair-wise comparisons identified areas of difference. CONCLUSION: The ASPN and possibly other similar practice-based research networks are sufficiently representative of family practice to serve as useful laboratories in which family practice and primary care can be explored.

Practice patterns of family physicians in practice-based research networks: a report from ASPN. Ambulatory Sentinel Pratice Network.

BACKGROUND: Practice-based research networks are growing and undertaking larger and more complex studies to inform the clinical practice of family physicians. We describe a study that compares clinical behaviors of physicians in the Ambulatory Sentinel Practice Network (ASPN), a large national practice-based research network, with those from the National Ambulatory Medical Care Survey (NAMCS). METHODS: A survey, replicating NAMCS, was conducted among 129 family physician members of ASPN. Nested logistic regression was used to determine which services could predict ASPN membership after adjustment for common and easily observed patient and physician characteristics. RESULTS: Of 20 specific patient services, only 4 were predictive of membership in ASPN. Of these 4, 2 were screening or diagnostic services; ASPN physicians were 1.18 times more likely to obtain a blood pressure measurement and 0.60 times as likely to order a culture for streptococcal pharyngitis. ASPN physicians were 2.30 times more likely to provide family planning counseling and 1.66 times more likely to provide smoking cessation counseling after adjusting for patient smoking status. CONCLUSIONS: We conclude that there are minimal differences in the practice patterns of family physicians participating in a large national practice-based research network and those included in the probability sample of NAMCS. Additional work is needed to examine further those characteristics of the phenomena observed in practice-based research network research that might affect generalizability of results to the larger community of practicing family physicians.