Selection bias from requiring patients to give consent to examine data for health services research.

BACKGROUND: New rulings nationwide require health services researchers to obtain patient consent before examining personally identifiable data. A selection bias may result if consenting patients differ from those who do not give consent. OBJECTIVE: To compare patients who consent, refuse, and do not answer. DESIGN: Patients completing an in-office survey were asked for permission to be surveyed at home and for their records to be reviewed. Survey responses and practice billing data were used to compare patients by consent status. SETTING: Urban family practice center. PATIENTS: Of 2046 eligible patients, 1106 were randomly selected for the survey, were approached by staff, and agreed to participate. Approximately 87% of the nonparticipants were eliminated through a randomization process. MAIN OUTCOME MEASURE: Consent status. RESULTS: A total of 33% of patients did not give consent: 25% actively refused, and 8% did not answer. Consenting patients were older, included fewer women and African Americans, and reported poorer physical function than those who did not give consent (P<.05). Patients who did not answer the question were older, included more women and African Americans, and were less educated than those who answered (P<.02). Visits for certain reasons (eg, pelvic infections) were associated with lower consent rates. On multivariate analysis, older age, male sex, and lower functional status were significant predictors of consent. CONCLUSIONS: Patients who release personal information for health services research differ in important characteristics from those who do not. In this study, older patients and those in poorer health were more likely to grant consent. Quality and health services research restricted to patients who give consent may misrepresent outcomes for the general population. Arch Fam Med. 2000;9:1111-1118

Evaluating the administration of an office-based health survey in a primary care practice.

Self-administered waiting room questionnaires are popular tools for gathering health information from patients, but these data cannot be used for research purposes without confirming adequate sampling of the practice population and assessing the completeness and accuracy of patients' responses. Long-term data collection also requires avoiding an imposition on clinic operations. We developed a protocol to test these questions in a 9-week pilot study of 884 survey-eligible patients visiting a family practice clinic. We found an adequate proportion of eligible patients were approached (74%) and participated (89%), they provided relatively complete (82-98%) and accurate responses, and the impact on office operations was minimal (<2 min of staff time per participant). Some demographic differences in participation and survey item completion were identified. A systematic process for testing survey performance allowed us to not only document these findings, but also to rapidly identify problems and introduce solutions while the survey was in progress.

Is cigarette smoking associated with impaired physical and mental functional status? An office-based survey of primary care patients.

OBJECTIVE: To examine the relationship between cigarette smoking and self-reported physical and mental functional status. DESIGN: Cross-sectional survey of 837 patients visiting 2 family-practice centers. Patients completed a self-administered survey about functional status, tobacco use, and demographic characteristics while waiting to be called back for their appointments. SETTING: An inner-city family practice clinic in Richmond, Virginia, and a more affluent suburban practice outside Washington, DC. MAIN OUTCOME MEASURES: Physical and mental functional status, as measured by the SF-36 (Medical Outcomes Trust, Boston, MA); current and former cigarette use; and demographic variables (age, gender, education, income). RESULTS: Among current smokers, self-reported functional status scores were significantly lower than those of nonsmokers in all SF-36 domains (p < or = 0.02), a pattern that was more dramatic for mental functional status domains (social function, vitality, emotional role limitations, mental health). In several SF-36 domains, a dose-response relationship between smoking and functional status was noted. After multivariate adjustment for demographic confounders and practice site, the statistical significance of these differences diminished considerably, but it remained significant for certain domains and for the overall difference across all domains (MANCOVA p = 0.017). CONCLUSIONS: Current smokers report lower functional status than nonsmokers, in physical and especially in mental domains. The meaning of this cross-sectional relationship is unclear without further longitudinal study. Smoking may be associated with other variables that have a causal role.

The Virginia generalist initiative: lessons learned in a statewide consortium.

In response to Virginia's need for an increased supply of generalist physicians, the state's three medical schools--Eastern Virginia Medical School, Virginia Commonwealth University School of Medicine, and the University of Virginia School of Medicine--have formed a partnership with key governmental stakeholders in the Virginia Generalist Initiative funded by The Robert Wood Johnson Foundation's Generalist Physician Initiative. These state-supported medical schools historically have functioned independently, with little cooperative effort. This paper describes the consortium, its activities, its successes, and its unmet objectives, and uses a series of cases in point to illustrate relevant lessons learned. Some of these lessons are that (1) stakeholders must be involved from the beginning of planning to identify mutual goals and establish consortium protocols; (2) all partners must share a philosophical commitment to the consortium's mission, as well as the time and resources needed; (3) an atmosphere that enables risk-taking behavior must be created; (4) stakeholders must be willing to revise goals and sustain an environment conductive to change; and (5) trust is essential and must be vigilantly maintained. The paper concludes that the Virginia Generalist Initiative has dramatically altered the goals, objectives and programs of the three schools and has succeeded in aligning the schools' strategic objectives with the state's priorities.

The functional status of inner-city primary care patients. Diminished function in a family practice population and its potential determinants.

BACKGROUND: Research on health care quality and effectiveness often relies on global health status measures, such as functional status, but little is known about the functional status of patients in the primary care setting (without limitation to specific diseases) and even less about the function of the poor or ethnic minorities. In preparation for a planned practice-based research network, we administered a functional-status survey to patients visiting an inner-city family practice center. METHODS: Over 9 weeks, 555 established patients older than 18 years, as well as adolescents accompanied by a parent or guardian, completed a survey that included the SF-36 Health Survey and questions about demographic variables and cigarette use. The survey was self-administered in the waiting area and examination room, and patients received no assistance from staff. RESULTS: Functional-status scores reported by this primary care cohort were significantly lower than those of the general population (P < .001) and comparable with those reported nationally for patients with chronic diseases (e.g., congestive heart failure, diabetes). Functional-status scores were associated with age, sex, and, most strikingly, socioeconomic status. For example, patients with a yearly income of less than $15,000 had lower mean physical function scores than those reported nationally for patients with hypertension, diabetes, depression, recent myocardial infarction, or hypertension (P < .05). Patients who currently smoked reported lower physical function (P = .004) and strikingly lower mental function (P < .001) than nonsmokers. CONCLUSIONS: Although patients completing the survey included healthy persons seeking preventive care and sick patients with acute and chronic illnesses, their overall functional status resembled that reported nationally for patients with chronic disease, perhaps reflecting the influence of poverty. Few studies have reported the association we observed between smoking and lower functional status. Further longitudinal studies in the primary care setting are necessary to fully interpret these associations and to evaluate the true impact of interventions on outcomes.

Primary-care--physician supply: policy analysis on the state level.

OBJECTIVE: To describe a method for policy analysis on the state level for understanding frequently overlooked determinants of the current status and dynamics of primary-care-physician supply. DESIGN: The method used is systems analysis. The approach takes account of the changing interstate migration, tracking the professional origins of physicians, their uneven age distribution, and the considerable time delays in the system. The forecasting mathematical model consists of the physician-aging submodel, the undergraduate and graduate medical education submodel, and the migration subsystem. SETTING: The necessary data were restored fully from the Virginia Board of Medicine archive database. RESULTS: The analysis shows the outstanding importance of out-of-state migration for the state of Virginia: approximately two thirds of primary-care physicians are out-of-state medical graduates. In the next decade, the attrition of primary-care physicians will start to increase steadily because of the prominent bulge in the physician age distribution. Similar bulges were observed in the age distributions for some other states. CONCLUSIONS: The method reveals the underlying mechanisms and principles of physician work-force reproduction. It may show which goals are feasible, and it may be used in any state for the research necessary for rational policy formulation.

Behind the physician licensure numbers: false impressions, retirement crisis, and migration.

This communication examines the supply of primary-care physicians at the state level. It shows that the number of actively practicing physicians is considerably less than the number of licensed physicians; the age distribution of primary-care physicians has a bulge in the ages younger than 50, and this bulge may lead in the near future to an unexpected increase in physician attrition due to retirement; and, at the state level, migration may be playing the dominant role in determining the total supply of primary-care physicians.

Success strategies for departments of family medicine.

Strong departments of family medicine in academic medical centers help assure the future scope and quality of family practice patient care, the ongoing evolution of family medicine as a scholarly discipline, and a continued flow of qualified medical school graduates into family practice residency programs and eventually into practice. This report presents key strategies of six successful departments of family medicine and describes the methods and skills considered important by the leaders of these departments. Common themes that emerge are (1) recruit and mentor the best faculty, (2) build a reputation for clinical excellence of faculty and residents, (3) become part of schoolwide curriculum activities, (4) establish a scholarly presence, and (5) develop networks of support.

A family practice education system based on patient care outcomes in family practice settings.

The philosophy, goals, objectives, methodology, and results of a family practice faculty development program are described. Developing family practice educators who will create an education system based on patient care outcomes in family practice settings is the central philosophical purpose of this faculty development program. On completion of the program all participants recognized the essential nature of this philosophical goal and were more comfortable and confident in their ability to: (1) determine resident learning needs; (2) organize curriculum units; (3) use different teaching techniques; and (4) understand their own personal teaching needs and interests. The implications of these changes for developing a family practice curriculum based on patient needs are described.

Low back pain in the primary care setting.

A study of the natural presentation, course, and treatment of low back pain in the primary care setting was undertaken. One hundred and forty-four charts listing low back pain as a problem were reviewed at a family practice center for a period of one year. A profile of the patient evaluated by the primary care physician emerged, revealing a high incidence of associated weight problems (70 percent), psychologic problems (33 percent), and hypertension (19 percent). The rate of actual or suspected disc disease (1.4 percent) was much lower than that reported in series from referral centers. This study of low back pain in the primary care setting illustrates the usefulness of outpatient study in defining a problem category, recognizing disease as a symptom complex, suggesting modalities of treatment, and designing a curriculum for the primary care physician.

Primary hyperparathyroidism in the primary care setting.

A series of 36 patients with surgically proved primary hyperparathyroidism is reported. From this group a clinical profile consisting of obesity, anxiety, and/or depression in a mildly hypertensive, middleaged female was derived. Women constituted 92 percent of the patients. The serum calcium was confirmed again as the single most valuable test in the evaluation of this disorder.

Central hypoventilation during quiet sleep in two infants.

Expired ventilation (VE), tidal volume (VT), frequency (f), and alveolar PCO2 (PACO2) were examined in six normal infants at 41 to 52 weeks post-conceptional age and in two infants who were apneic at birth. Their response to breathing 5% carbon dioxide in air and to 100% oxygen in quiet sleep were compared to those in rapid eye movement (REM) sleep. VE in normal infants was 259 ml/kg/min in REM and 200.2 ml/kg/min in quiet sleep with the difference being due to decreased carbon dioxide production and to decreased dead space. VE increased 34.4 ml/kg/min/mm Hg of PCO2 elevation with 5% carbon dioxide breathing during REM and was not significantly different during quiet sleep. During oxygen breathing VE fell by 32.7% at 30 seconds before increasing again. In the affected infants, VE and PACO2 during REM at 1 and 4 months were normal. At 1 month, during quiet sleep, each infant became apneic and PACO2 rose 9 and 8 mm Hg/min respectively. At this time mechanical ventilation was begun. At 4 months, during quiet sleep, VE was 0.064 and 0.063 ml/kg/min at PACO2 of 66 mm Hg in each infant. The change was due entirely to a decrease in VT to 2.3 and 2.5 ml/kg. At this time 5% carbon dioxide breathing given during normal ventilation in REM produced an abrupt fall in VT to 2.0 and 2.2 ml/kg with no change in frequency. Oxygen breathing during REM at one month had no effect but at 4 months produced apnea requiring mechanical ventilation after one minute. The findings suggest that the ventilatory response to carbon dioxide is (1) important in initiation of extrauterine ventilation and (2) in sustaining ventilation particularly in quiet sleep. It is not necessary in sustaining ventilation awake or in REM sleep and it represents a balance between the stimulatory and depressant effects of carbon dioxide on the central nervous system.

A data bank for patient care, curriculum, and research in family practice: 526,196 patient problems.

The health care problems that 88,000 patients presented to 118 family physicians over two years were evaluated. As a result, 526,196 health care problems were noted. Ninety percent of all problems were contained within 169 descriptive problems using the RCGP coding system for primary care. Knowledge of the profile of patient problems as they present to the family physician will alow for the development of a logical curriculum for the family practice resident and of patient care systems in family medicine. An appropriate methodology for the development of curriculum is discussed.

The afferent vagus and regulation of breathing in response to inhaled CO2 in awake newborn lambs.

Changes in steady state minute ventilation, tidal volume and frequency were determined in unanesthetized lambs before and after bilateral cervical vagotomy while breathing 3, 6, and 9% CO2 in 20% O2 balance N2. The slope of delta VE/delta PaCO2 fell from 0.068 to 0.033 while frequency response depended on intact vagi. Electrical stimulation of the cut proximal vagus (after bilateral vagotomy) restored CO2 responsiveness to control values. From these observations, it may be concluded that the afferent vagus is involved in the control of ventilation during hypercapnia and helps to modulate ventilatory frequency by inhibiting tidal volume.