Biomedical subjects

P A Margolis

Publications and source records attributed to P A Margolis.

At least 19 recordsLinked to original sources

PubMed2001

The association of socioeconomic status with outcomes in cystic fibrosis patients in the United States.

There is considerable variability in the clinical course of disease in cystic fibrosis (CF). Although currently unidentified modifier genes might explain some of this heterogeneity, other factors are probably contributory. Socioeconomic status (SES) is an important predictor of health status in many chronic polygenic diseases, but its role in CF has not been systematically evaluated. We performed a historical cohort analysis of pediatric CF patients in the United States using National Cystic Fibrosis Foundation Patient Registry (NCFPR) data for 1986 to 1994, and used Medicaid status as a proxy for low SES. The adjusted risk of death was 3.65 times higher (95% confidence interval [CI]: 3.03 to 4.40) for Medicaid patients than for those not receiving Medicaid. The percent predicted FEV(1) of surviving Medicaid patients was less by 9.1% (95% CI: 6.9 to 11.2). Medicaid patients were 2.19 times more likely to be below the 5th percentile for weight (95% CI: 1.91 to 2.51) and 2.22 times more likely to be below the 5th percentile for height (95% CI: 1.95 to 2.52) than were non-Medicaid patients. Medicaid patients were 1.60 times more likely to require treatment for a pulmonary exacerbation (95% CI: 1.29 to 1.98). There was no difference in the number of outpatient clinic visits for Medicaid and non-Medicaid patients. We conclude that low SES is associated with significantly poorer outcomes in children with CF. Barriers in access to specialty health care do not seem to explain this difference. Further study is indicated to determine what adverse environmental factors might cluster in CF patients of low SES to cause worse outcomes.

Cause of Death↗

PubMed2001

Improving preventive service delivery through office systems.

OBJECTIVE: Rates of childhood immunizations and other preventive services are lower in many practices than national goals and providers' own estimates. Office systems have been used in adult settings to improve the delivery of preventive care, but their effectiveness in pediatric practices is unknown. This study was designed to determine whether a group of primary care practices in 1 community could implement office-based quality improvement systems that would significantly improve their delivery of childhood preventive services. The study was part of a larger community-wide intervention study reported in a preceding study. METHODS: All the major providers of primary care to children in 1 community were recruited and agreed to participate (N = 8 practices). Project staff worked on-site with improvement teams in each practice to develop tailored systems to assess and improve the delivery of immunizations and screening for anemia, tuberculosis, and lead exposure. Office-based quality improvement systems typically involved some combination of chart prescreening, risk assessment forms, Post-it prompts, flow-sheets, reminder/recall systems, and patient education materials. Office systems also often involved redistributing responsibilities among office staff. RESULTS: All 8 participating practices created improvement teams. Project staff met with the practices 10 to 15 times over 12 months. After the period of office assistance, the overall rates for all preventive services except tuberculosis screening increased by amounts that were both clinically and statistically significant. Absolute percent improvements included: complete immunizations at 12 months, 7%; complete immunizations at 24 months, 12%; anemia screening, 30%; lead screening, 36%. The amount of improvement achieved varied considerably between practices. CONCLUSIONS: Office systems and the principles of quality improvement that underlie them seem to be effective in improving the delivery of childhood preventive services. Important predisposing factors may exist within practices that affect the likelihood that an individual practice will make significant improvements. prevention, immunizations, improvement, office systems, primary care.

Child↗

PubMed2001

From concept to application: the impact of a community-wide intervention to improve the delivery of preventive services to children.

OBJECTIVE: To improve health outcomes of children, the US Maternal and Child Health Bureau has recommended more effective organization of preventive services within primary care practices and more coordination between practices and community-based agencies. However, applying these recommendations in communities is challenging because they require both more complex systems of care delivery within organizations and more complex interactions between them. To improve the way that preventive health care services are organized and delivered in 1 community, we designed, implemented, and assessed the impact of a health care system-level approach, which involved addressing multiple care delivery processes, at multiple levels in the community, the practice, and the family. Our objective was to improve the processes of preventive services delivery to all children in a defined geographic community, with particular attention to health outcomes for low-income mothers and infants. DESIGN: Observational intervention study in 1 North Carolina county (population 182 000) involving low- income pregnant mothers and their infants, primary care practices, and departments of health and mental health. An interrupted time-series design was used to assess rates of preventive services in office practices before and after the intervention, and a historical cohort design was used to compare maternal and child health outcomes for women enrolled in an intensive home visiting program with women who sought prenatal care during the 9 months before the program's initiation. Outcomes were assessed when the infants reached 12 months of age. INTERVENTIONS: Our primary objective was to achieve changes in the process of care delivery at the level of the clinical interaction between care providers and patients that would lead to improved health and developmental outcomes for families. We selected interventions that were directed toward major risk factors (eg, poverty, ineffective care systems for preventive care in office practices) and for which there was existing evidence of efficacy. The interventions involved community-, practice-, and family-level strategies to improve processes of care delivery to families and children. The objectives of the community-level intervention were: 1) to achieve policy level changes that would result in changes in resources available at the level of clinical care, 2) to engage multiple practice organizations in the intervention to achieve an effect on most, if not all, families in the community, and 3) to enhance communication between, among, and within public and private practice organizations to improve coordination and avoid duplication of services. The objective of the practice-level interventions was to overcome specific barriers in the process of care delivery so that preventive services could be effectively delivered. To assist the health department in implementing the family-level intervention, we provided assistance in hiring and training staff and ongoing consultation on staff supervision, including the use of structured protocols for care delivery, and regular feedback data about implementation of the program. Interventions with primary care practices focused on the design of the delivery system within the office and the use of teamwork and data in an "office systems" approach to improving clinical preventive care. All practices (N = 8) that enrolled at least 5 infants/month received help in assessing performance and developing systems (eg, preventive services flow sheets) for preventive services delivery. Family-level interventions addressed the process of care delivery to high-risk pregnant women (<100% poverty) and their infants. Mothers were recruited for the home visiting intervention when they first sought prenatal care at the community health center, the county's largest provider of prenatal care to underserved women. The home visiting intervention involved teams of nurses and educators and involved 2 to 4 visits per month through the infant's first year of life to provide parental education on fetal and infant health and development, enhance parents' informal support systems, and link parents with needed health and human services. We included training in injury prevention and discipline, and home visitors assisted mothers in obtaining care from one of the primary care offices. RESULTS: There were high levels of participation, changes in the organization of the delivery system, and improvements in preventive health outcomes. Agencies cooperated in joint contracting, staff training, and defining program eligibility. All 8 eligible practices agreed to participate and 7/8 implemented at least 1 new office system element. Of eligible women, 89% agreed to participate, and outcome data were available on 80% (180/225). After adjusting for differences in baseline characteristics, intervention group women were significantly more likely than comparison group women to use contraceptives (69% vs 47%), not smoke tobacco (27% vs 54%) and have a safe and stimulating home environment for their children. Intervention group children were more likely to have had an appropriate number of well-child care visits (57% vs 37%) and less likely to be injured (2% vs 7%). Intervention mothers also received Aid to Families with Dependent Children for fewer months after the birth of their child (7.7 months vs 11.3 months). CONCLUSIONS: We observed a number of positive effects at all 3 levels of intervention. Policy-level changes at the state and community led to lasting changes in the organization and financing of care, which enabled changes in clinical services to take place. These changes have now been expanded beyond this community to other communities in the state. We were also able to engage multiple practice organizations, reduce duplication, and improve the coordination of care. Changes in the process of preventive services delivery were noted in participating practices. Finally, the outcomes of the family-level intervention were comparable in direction and magnitude to the outcomes of previous randomized trials of the intervention. All the changes were achieved over a relatively brief 3-year study period, and many have been sustained since the project was completed. Tiered, interrelated interventions directed at an entire population of mothers and children hold promise to improve the effectiveness and outcomes of health care for families and children.

Adult↗

PubMed2000

Effect of patient reminder/recall interventions on immunization rates: A review.

CONTEXT: Immunization rates for children and adults remain below national goals. While experts recommend that health care professionals remind patients of needed immunizations, few practitioners actually use reminders. Little is known about the effectiveness of reminders in different settings or patient populations. OBJECTIVES: To assess the effectiveness of patient reminder systems in improving immunization rates, and to compare the effectiveness of different types of reminders for a variety of patient populations. DATA SOURCES: A search was performed using MEDLINE, EMBASE, PsychINFO, Sociological Abstracts, and CAB Health Abstracts. Relevant articles, as well as published abstracts, conference proceedings, and files of study collaborators, were searched for relevant references. STUDY SELECTION AND DATA EXTRACTION: English-language studies involving patient reminder/recall interventions (using criteria established by the Cochrane Collaboration) were eligible for review if they involved randomized controlled trials, controlled before-after studies, or interrupted time series, and measured immunization rates. Of 109 studies identified, 41 met eligibility criteria. Studies were reviewed independently by 2 reviewers using a standardized checklist. Results of studies are expressed as absolute percentage-point changes in immunization rates and as odds ratios (ORs). Studies with similar characteristics of patients or interventions were pooled (random effects model). DATA SYNTHESIS: Patient reminder systems were effective in improving immunization rates in 33 (80%) of the 41 studies, irrespective of baseline immunization rates, patient age, setting, or vaccination type. Increases in immunization rates due to reminders ranged from 5 to 20 percentage points. Reminders were effective for childhood vaccinations (OR, 2.02; 95% confidence interval [CI], 1.49-2.72), childhood influenza vaccinations (OR, 4. 25; 95% CI, 2.10-8.60), adult pneumococcus or tetanus vaccinations (OR, 5.14; 95% CI, 1.21-21.78), and adult influenza vaccinations (OR, 2.29; 95% CI, 1.69-3.10). While reminders were most effective in academic settings (OR, 3.33; 95% CI, 1.98-5.58), they were also highly effective in private practice settings (OR, 1.79; 95% CI, 1. 45-2.22) and public health clinics (OR, 2.09; 95% CI, 1.42-3.07). All types of reminders were effective (postcards, letters, and telephone or autodialer calls), with telephone reminders being most effective but costliest. CONCLUSIONS: Patient reminder systems in primary care settings are effective in improving immunization rates. Primary care physicians should use patient reminders to improve immunization delivery. JAMA. 2000;284:1820-1827.

Adult↗

PubMed2000

The effect of audit and feedback on immunization delivery: a systematic review.

OBJECTIVE: To assess the effective of audit and feedback (A&F) on immunization delivery by health care professionals. DESIGN: Systematic review of published literature. MAIN OUTCOME MEASURES: Changes in immunization rates. METHODS: We searched Medline between 1966 and 1997. We obtained additional studies from back-searching reference lists and the files of study collaborators. We included studies that were written in English, that included audit and feedback in at least one arm of the study, that studied universally recommended childhood or adult vaccines, and that provided immunization coverage data. Two reviewers read studies independently and abstracted using a validated checklist. Study quality was assessed using criteria standardized by the Cochrane Collaboration. Differences between reviewers were resolved by consensus. RESULTS: The search process resulted in 60 citations; 44 were fully reviewed and 15 met eligibility criteria. Five were randomized trials. Twelve of the fifteen studies found that A&F, alone or in combination with other interventions, were associated with improvements in immunization rates. The magnitude of the effect varied from -17% to +49% change. Study design heterogeneity precluded statistical pooling of study results. CONCLUSIONS: The evidence available from published studies suggests that A&F alone may be an effective strategy for improving immunization rates. The number of well-conducted studies is small, and the effect is variable. Additional well-designed studies are needed to identify the independent effects of A&F, optimal format and frequency of A&F, and to examine its long-term effect on provider immunization practices and costs.

Adult↗

PubMed1999

A systematic review of vision screening tests for the detection of amblyopia.

OBJECTIVE: To review the test characteristics and the quality of evidence regarding available screening tests for the detection of amblyopia in preschool-aged children to help primary care practitioners select a screening strategy. DESIGN: Systematic review of published studies. DATA SOURCES: The MEDLINE database was searched from 1966 through January 1999 using a broad and inclusive strategy. A total of 9551 citations were identified. STUDY SELECTION: All studies that compared the results of commercially available screening tests in preschool-aged children to ophthalmologic examination. DATA EXTRACTION: The setting of the study, the age of the population, the type of screening test, criteria for a positive screen, criteria for the ophthalmologic examination, test characteristics, and measures of reliability were abstracted by 2 reviewers for each selected study. DATA SYNTHESIS: Four eligible articles were identified that studied the test characteristics of 3 screening tests. None of these studies were performed in a primary care setting. Each study used different criteria for failure of the ophthalmologic examination. None of the studies measured observer or test reliability. CONCLUSIONS: Few high-quality data exist regarding the performance of preschool vision screening. Important future work should include the development of a consensus gold standard ophthalmologic examination and evaluation of screening tests in the primary care setting.

Amblyopia↗

PubMed1998

Development of a clinical prediction model for an ordinal outcome: the World Health Organization Multicentre Study of Clinical Signs and Etiological agents of Pneumonia, Sepsis and Meningitis in Young Infants. WHO/ARI Young Infant Multicentre Study Group.

This paper describes the methodologies used to develop a prediction model to assist health workers in developing countries in facing one of the most difficult health problems in all parts of the world: the presentation of an acutely ill young infant. Statistical approaches for developing the clinical prediction model faced at least two major difficulties. First, the number of predictor variables, especially clinical signs and symptoms, is very large, necessitating the use of data reduction techniques that are blinded to the outcome. Second, there is no uniquely accepted continuous outcome measure or final binary diagnostic criterion. For example, the diagnosis of neonatal sepsis is ill-defined. Clinical decision makers must identify infants likely to have positive cultures as well as to grade the severity of illness. In the WHO/ARI Young Infant Multicentre Study we have found an ordinal outcome scale made up of a mixture of laboratory and diagnostic markers to have several clinical advantages as well as to increase the power of tests for risk factors. Such a mixed ordinal scale does present statistical challenges because it may violate constant slope assumptions of ordinal regression models. In this paper we develop and validate an ordinal predictive model after choosing a data reduction technique. We show how ordinality of the outcome is checked against each predictor. We describe new but simple techniques for graphically examining residuals from ordinal logistic models to detect problems with variable transformations as well as to detect non-proportional odds and other lack of fit. We examine an alternative type of ordinal logistic model, the continuation ratio model, to determine if it provides a better fit. We find that it does not but that this model is easily modified to allow the regression coefficients to vary with cut-offs of the response variable. Complex terms in this extended model are penalized to allow only as much complexity as the data will support. We approximate the extended continuation ratio model with a model with fewer terms to allow us to draw a nomogram for obtaining various predictions. The model is validated for calibration and discrimination using the bootstrap. We apply much of the modelling strategy described in Harrell, Lee and Mark (Statist. Med. 15, 361-387 (1998)) for survival analysis, adapting it to ordinal logistic regression and further emphasizing penalized maximum likelihood estimation and data reduction.

Chi-Square Distribution↗

PubMed1998

Relationship between socioeconomic status and disease severity in cystic fibrosis.

OBJECTIVE: This study was carried out to evaluate whether patients with cystic fibrosis (CF) who are socioeconomically disadvantaged, have a different outcome than higher-income patients. Medicaid insurance coverage was used as a proxy of low family income. STUDY DESIGN: A cross-sectional analysis was performed on a group of patients younger than 21 years of age seen at the University of North Carolina CF Center in 1994. RESULTS: The difference in median age at diagnosis for Medicaid (132 days) and non-Medicaid (177 days) patients was not statistically significant (p = 0.17). Medicaid patients' mean maximum percent predicted forced expiratory volume in 1 second for the year was 11.6% less than that of the non-Medicaid group (p = 0.01); this difference was constant across age. Medicaid patients averaged 0.8 more admissions for the year (p < 0.01) and 8.8 more days (p < 0.01) in the hospital but received the same amount of outpatient intravenous therapy. They also had 1.20 more outpatient visits to the center during the year (p = 0.02). CONCLUSIONS: Medicaid patients with CF have worse lung function and require more treatment for pulmonary exacerbations than their more advantaged counter-parts. This difference appears to begin early in life, does not increase with age, and is not explained by inadequate access to outpatient specialty care or delayed diagnosis. Other explanations such as inadequate access to primary care, poor adherence to prescribed regimens, or greater exposure to pollutants (e.g., environmental tobacco smoke) are speculative.

Adolescent↗

PubMed1998

Home visitors' beliefs and practices regarding childhood injury prevention.

Injuries are the leading cause of death for children under age 19. Prevention efforts focus on eliminating hazards or changing individuals' behavior. Few interventions address psychosocial factors that contribute to injuries. Home visiting programs target families' functioning and help parents overcome, barriers that inhibit their readiness and ability to address injury prevention. This study, a telephone interview with 87 public health nurses and social workers, assessed home visitors' preparedness to address childhood injury prevention, their practices and factors influencing their ability to undertake injury prevention activities. Results showed that 41% of home visitors talked to parents about injury prevention during visits. To identify hazards, most visitors (81%) assessed the home environment as they did other things; 51% never used a home safety checklist. Most home visitors discussed hot water temperature (82%), smoke detectors (76%), and firearms (50%). To respond to hazards, most relied on verbal education. Other priorities and time constraints were major barriers to injury prevention activities. Home visitors' beliefs in the importance of injury prevention and willingness to implement strategies suggest that home visiting can be an effective delivery strategy for injury prevention. It is important to consider how to include, in a systematic manner, injury prevention in home visitor training.

Accidents, Home↗

PubMed1997

Urinary cotinine and parent history (questionnaire) as indicators of passive smoking and predictors of lower respiratory illness in infants.

Studies of the effects of passive smoking on lower respiratory illness (LRI) have relied on questionnaires to measure exposure. We studied the association between two measures of passive smoking and the incidence of acute LRI in infants. We analyzed data from a community-based cohort study of respiratory illness during the first year of life in North Carolina. The incidence of LRI was determined by telephone calls at 2-week intervals. Environmental, demographic, and psychosocial risk factors for LRI were measured during home interviews. Tobacco smoke exposure was measured as the mean number of cigarettes smoked per day in the infant's presence. Smoke absorption by the infants was measured by the urinary cotinine/ creatinine ratio. Of the 485 infants in the study, 325 (67%) had telephone follow-up and at least two home interviews. In bivariate analyses, reported tobacco smoke exposure and urinary cotinine were associated with LRI. Only the association between reported exposure and LRI remained significant after adjusting for confounders, [adjusted incidence of LRI (episodes/child-year) non-exposed: 0.6; < or = 10 cigarettes/day: 0.9 (RR 1.5, 95% CI: 1.1, 2.0); > 10 cigarettes/day: 1.3 (RR 2.2, 95% CI: 1.3, 3.8)]. We conclude that infants reportedly exposed to tobacco smoke have an increased incidence of LRI. There are differences between questionnaire and biochemical measures of passive smoking. Urinary cotinine will not necessarily improve the validity of studies of the relationship of passive smoking to LRI in infants.

Adult↗

PubMed1996

Linking clinical and public health approaches to improve access to health care for socially disadvantaged mothers and children. A feasibility study.

OBJECTIVE: To test the feasibility of combining home- and office-based interventions to improve access to health care and health outcomes of Medicaid-eligible mothers and infants. DESIGN: Randomized trial in 2 counties in North Carolina (1 rural, 1 urban). Information on health and developmental outcomes was obtained by face-to-face interviews, medical chart abstractions, hospital medical records, and state data tapes. PARTICIPANTS: Ninety-three Medicaid-eligible first-time pregnant women in their third trimester and their subsequently born infants, who were followed up until they were 6 months old, and 3 pediatric practices and 1 family practice. INTERVENTIONS: Coordinated home visit and office intervention, office intervention, and usual care. Home visits by 3 public health nurses provided parental education and social support and linked families with needed community resources. Women in the office intervention group were encouraged to seek health care for their infants from one of the primary care practices. Participating offices received assistance with Medicaid billing, help developing a system to improve preventive care, and customized patient education materials. RESULTS: Mothers reported that the nurses helped them in areas related to the content of the program. An office system for prevention was developed and implemented in all 4 practices for study patients. Families in the intervention groups were more likely than control families to have had a prenatal visit with a pediatrician (P = .01, chi 2), a primary care office as the regular source of sick care (P = .02, chi 2), and less waiting time (P = .02, Student t test). They were also more likely to recall receiving patient education materials (P = .007, chi 2). CONCLUSIONS: It is feasible to link clinical and public health approaches to improve the quality and effectiveness of care for socially disadvantaged children. Such interventions should be tested in defined populations.

Child Health Services↗

PubMed1996

The delivery of immunizations and other preventive services in private practices.

OBJECTIVES: To measure the proportion of children cared for in private practices who are fully immunized and have been screened for anemia, tuberculosis (TB), and lead poisoning by 2 years of age. DESIGN: Cross-sectional chart review. SETTING: Fifteen private pediatric practices in central North Carolina (11 chosen randomly). PATIENTS: One thousand thirty-two randomly selected 2-year-old children. MAIN OUTCOME MEASURES: Proportion of children immunized and screened for anemia, TB and lead poisoning by 24 months of age and immunization and screening rates of the practices. RESULTS: Sixty-one percent of the children were fully immunized at 24 months of age; the rates among practices varied widely (38% to 82%). Sixty-eight percent of the children had been screened for anemia, 57% had been screened for TB, and 3% had been screened for lead poisoning. Physicians overestimated the proportions of fully immunized children in their practices by an average of 10% (range, -3% to 17%). The median number of well child visits by 2 years of age was 5 (range, 0 to 14), and only 19% of the entire sample made 8 or more well child visits, the number recommended by the American Academy of Pediatrics in the first 18 months of life. The numbers of well child and non-well child visits were the strongest predictors of complete immunization. Practice characteristics associated with being fully immunized included the use of preventive services prompting sheets (eg, flow sheets) in the medical records, not seeing the same physician for all well child care, and having nurses review patients' immunization status during their visits to the office. CONCLUSIONS: Underimmunization and inadequate screening are significant problems in private pediatric practices in North Carolina. Physicians are unaware of the rates of underimmunization in their offices.

Anemia↗

PubMed1995

The rest of the access-to-care puzzle. Addressing structural and personal barriers to health care for socially disadvantaged children.

A mother brings her 2-year-old child to the office at 4:30 Friday afternoon. The child has been seen only once in the practice for an episode of otitis media. The child missed her follow-up appointment. When the receptionist asks why the child is here, the mother responds that she was able to get a ride today with a neighbor who has an appointment with another physician in the practice. The child is not covered by health insurance. The mother did not bring her immunization record and is not certain what preventive care the child has received in the past.

Child Health Services↗

PubMed1994

Application of sample survey methods for modelling ratios to incidence densities.

We describe ratio estimation methods for multivariately analysing incidence densities from prospective epidemiologic studies. Commonly used in survey data analysis, these ratio methods require minimal distributional assumptions and take into account the random variability in the at-risk periods. We illustrate their application with data from a study of lower respiratory illness (LRI) in children during the first year of life. One question of interest is whether children with passive exposure to tobacco smoke have a higher rate of LRI, on average, than those with no exposure and in a setting where age of child and season are taken into account. A second question is whether the relationship persists after adjusting for background variables such as family's socioeconomic status, crowding in the home, race, and type of feeding. The basic strategy consists of a two-step process in which we first estimate subgroup-specific incidence densities and their covariance matrix via a first-order Taylor series approximation. These estimates are used to test for differences in marginal rates of LRI between children exposed to tobacco smoke and those not exposed. We then fit a log-linear model to the estimated ratios in order to test for significant covariate effects. The ability to produce direct estimates of adjusted incidence density ratios for risk factors of interest is an important advantage of this approach. For comparison purposes and to address the limitations of the ratio method with respect to the number of covariates that can be controlled simultaneously, we consider survey logistic regression methods for the example data as well as logistic and Poisson regression models fitted via generalized estimating equation methods. Although the analysis strategy is illustrated with illness data from an epidemiologic study, the context of application is broader and includes, for example, data on adverse events from a clinical trial.

Bronchitis↗

PubMed1994

Accuracy of the clinical examination in detecting hypoxemia in infants with respiratory illness.

OBJECTIVES: To evaluate the diagnostic accuracy of the clinical examination in detecting hypoxemia in infants with lower respiratory tract illness. DESIGN: Cross-sectional study. SETTING: Three university pediatric outpatient departments and one private pediatric practice. PATIENTS: Healthy infants less than 1 year of age seen between December and March 1989 and 1990, with symptoms suggesting acute lower respiratory tract illness. MAIN OUTCOME MEASURES: The test characteristics of 27 elements of the clinical examination, as well as the accuracy of the overall examination and the components of the examination in detecting oxygen saturation < 95% measured by pulse oximetry. Reliability of clinical examination findings. RESULTS: None of the 27 clinical findings had sensitivities that would make them useful diagnostic tests for hypoxemia. By combining all the clinical findings, however, we found good diagnostic accuracy (area under the receiver operator characteristic curve 0.90). Three groups of clinical findings--social interactiveness, respiratory effort, and physical appearance--accounted for much of the diagnostic accuracy of the examination. Auscultatory findings contributed little. In these three groups, five clinical findings accounted for almost all the accuracy: attentiveness, consolability, respiratory effort, color, and movement. Together, these findings also had good accuracy (area under the receiver operator characteristic curve 0.95). CONCLUSIONS: A small number of clinical observations may be mostly responsible for the diagnostic value of the clinical examination of infants with symptoms of LRI. Concentrating on a limited group of findings appears to enhance the accuracy of the examination in detecting hypoxemia.

Cross-Sectional Studies↗

PubMed1993

Verification bias in pediatric studies evaluating diagnostic tests.

Improperly designed evaluations of diagnostic tests may lead to inaccurate conclusions about a test's accuracy. One problem, verification bias, occurs if subjects are not equally likely to have the diagnosis verified by a gold-standard evaluation and if selection for further evaluation is dependent on the diagnostic test result. To determine whether verification bias is a problem in pediatric studies of diagnostic tests, we conducted a critical appraisal of all studies evaluating diagnostic tests published in three pediatric journals during a 3-year period. Thirty-six percent were subject to verification bias. The most prevalent cause was restriction of the patient sample to those whose diagnosis had been verified by a gold standard evaluation, when the decision to obtain the gold standard was influenced by the diagnostic test result. Verification bias may have serious effects on the estimated sensitivity and specificity of a test. Improved awareness of the potential for verification bias may help physicians improve their selection and interpretation of diagnostic tests and thereby improve the quality and efficiency of patient care.

Bias↗

PubMed1992

Factors associated with pediatricians' participation in Medicaid in North Carolina.

OBJECTIVE: To describe the relative importance of factors influencing pediatricians' participation in Medicaid in North Carolina. DESIGN: Questionnaire survey. SETTING AND PARTICIPANTS: Nonacademic primary care pediatricians in direct patient care at least 50% of the time; 332 (85%) of the 389 eligible pediatricians responded. MAIN OUTCOME MEASURES: Proportion of pediatricians who restricted Medicaid patients' access to their practices. The association between restricting access and the following factors was assessed: Medicaid reimbursement, pediatricians' demographic characteristics, knowledge of the Medicaid program, attitudes toward Medicaid patients and the Medicaid program, and beliefs about whether other physicians were available to care for Medicaid patients. RESULTS: Twenty-nine percent of pediatricians restricted Medicaid patients' access to their practices. The proportion of pediatricians restricting access was 62% in cities, 13% in medium-sized towns, and 12% in small towns (P less than .001), but the proportion of pediatricians in cities who restricted access varied from 87% to 22%. Pediatricians who received a higher proportion of their usual fee were less likely to restrict Medicaid patients' access. The relationship between Medicaid payment and restricted access was substantially weakened after controlling for the following factors: (1) the size of the community, (2) pediatricians' attitudes toward Medicaid payment, (3) their perceptions that they were too busy to care for Medicaid patients, and (4) whether there were other resources for the care of Medicaid patients. At comparable levels of payment, rural pediatricians were about six times less likely than urban pediatricians to restrict access. Pediatricians who knew less about Medicaid reimbursement also restricted access more often. Whether or not they restricted access to new Medicaid patients, pediatricians provided acute, preventive, hospital, and emergency care to the Medicaid patients who were already in their practices. CONCLUSIONS: Existing resources for the care of Medicaid patients, pediatricians' economic dependence on Medicaid, and the local norms of practice may be important factors in pediatricians' decision to participate in Medicaid. Increasing reimbursement will have only modest effects on Medicaid participation. Strategies to improve participation should also address pediatricians' knowledge of the Medicaid program and enlist the support of community physicians.

Attitude of Health Personnel↗

PubMed1992

Lower respiratory illness in infants and low socioeconomic status.

OBJECTIVES: Infants from families of low socioeconomic status are said to suffer higher rates of lower respiratory illness, but this assertion has not been carefully examined. METHODS: We studied the frequency and determinants of lower respiratory illness in infants of different socioeconomic status (n = 393) by analyzing data from a community-based cohort study of respiratory illness during the first year of life in central North Carolina. RESULTS: The incidence of lower respiratory illness was 1.41 in the low socioeconomic group, 1.26 in the middle group, and 0.67 in the high group. The prevalence of persistent respiratory symptoms was 39% in infants in the low socioeconomic group, 24% in infants in the middle group, and 14% in infants in the high group. The odds of persistent respiratory symptoms in infants of low and middle socioeconomic status were reduced after controlling for environmental risk factors for lower respiratory illness. Enrollment in day care was associated with an increased risk of persistent symptoms among infants of high but not low socioeconomic status. CONCLUSIONS: Infants of low socioeconomic status are at increased risk of persistent respiratory symptoms. This risk can be partly attributed to environmental exposures, most of which could be changed.

Acute Disease↗