Biomedical subjects

Simon J Hambidge

Publications and source records attributed to Simon J Hambidge.

12 recordsLinked to original sources

PubMed2007

Disparities in pediatric preventive care in the United States, 1993-2002.

OBJECTIVES: To quantify physician-reported preventive counseling and screening during well-child visits (WCVs) and to examine racial and ethnic disparities in these activities. DESIGN: Cross-sectional study using the National Ambulatory Medical Care Survey, January 1993 through December 2002. SETTING: Office-based physician practices. PARTICIPANTS: Children from birth to 18 years old who were seen by a physician for a WCV. MAIN OUTCOME MEASURE: Preventive counseling and screening. RESULTS: Well-child visits were shorter for Latino children than for white or black children. At WCVs, white children were more likely to receive preventive counseling than were black or Latino children (72% vs 61% vs 61%, respectively; P = .01) but not more likely to receive screening for elevated blood pressure, anemia, vision and hearing acuity, or lead toxicity. There were no differences in secondary diagnoses made at WCVs for white, black, or Latino children (15% vs 17% vs 14%, respectively; P = .65). The children who received the least counseling were Latino children in the public sector non-health maintenance organization setting (counseled at 39% of visits) and Latino children who self-paid for the visits (counseled at 26% of visits). After adjusting for possible confounders, including medications prescribed at the visit, black and Latino children were less likely to receive counseling than were white children (odds ratios, 0.68 and 0.63; 95% confidence interval, 0.48-0.97 and 0.44-0.90, respectively), and black children were less likely to receive preventive screening services (odds ratios, 0.65; 95% confidence interval, 0.45-0.93). CONCLUSIONS: By physician report in a nationally representative sample, black and Latino children received less counseling at WCVs than did white children. These disparities were unexplained by the competing demands of other secondary diagnoses or medications prescribed or dispensed.

Adolescent↗

PubMed2006

Safety of trivalent inactivated influenza vaccine in children 6 to 23 months old.

CONTEXT: Beginning with the winter season of 2004-2005, influenza vaccination has been recommended for all children 6 to 23 months old in the United States. However, its safety in young children has not been adequately studied in large populations. OBJECTIVE: To screen for medically attended events in the clinic, emergency department, or hospital after administration of trivalent inactivated influenza vaccine in children 6 to 23 months old. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort using self-control analysis, with chart review of significant medically attended events at 8 managed care organizations in the United States that comprise the Vaccine Safety Datalink. Participants were all children in the Vaccine Safety Datalink cohort 6 to 23 months old who received trivalent inactivated influenza vaccine between January 1, 1991, and May 31, 2003 (45,356 children with 69,359 vaccinations). MAIN OUTCOME MEASURE: Any medically attended event significantly associated with trivalent inactivated influenza vaccine in risk windows 0 to 3 days, 1 to 14 days (primary analysis), 1 to 42 days, or 15 to 42 days after vaccination, compared with 2 control periods, one before vaccination and the second after the risk window. All individual ICD-9 codes as well as predefined aggregate codes were examined. RESULTS: Before chart review, only 1 diagnosis, gastritis/duodenitis, was more likely to occur in the 14 days after trivalent inactivated influenza vaccine (matched odds ratio [OR], 5.50; 95% confidence interval [CI], 1.22-24.81 for control period 1, and matched OR, 4.33; 95% CI, 1.23-15.21 for control period 2). Thirteen medically attended events were less likely to occur after trivalent inactivated influenza vaccine, including acute upper respiratory tract infection, asthma, bronchiolitis, and otitis media. After chart review, gastritis/duodenitis was not significantly associated with trivalent inactivated influenza vaccine (matched OR, 4.00; 95% CI, 0.85-18.84 for control period 1; matched OR, 3.34; 95% CI, 0.92-12.11 for control period 2). CONCLUSIONS: In the largest population-based study to date of the safety of trivalent inactivated influenza vaccine in young children, there were very few medically attended events, none of which were serious, significantly associated with the vaccine. This study provides additional evidence supporting the safety of universally immunizing all children 6 to 23 months old with influenza vaccine.

Cohort Studies↗

PubMed2006

Four different study designs to evaluate vaccine safety were equally validated with contrasting limitations.

OBJECTIVE: We conducted a simulation study to empirically compare four study designs [cohort, case-control, risk-interval, self-controlled case series (SCCS)] used to assess vaccine safety. STUDY DESIGN AND METHODS: Using Vaccine Safety Datalink data (a Centers for Disease Control and Prevention-funded project), we simulated 250 case sets of an acute illness within a cohort of vaccinated and unvaccinated children. We constructed the other three study designs from the cohort at three different incident rate ratios (IRRs, 2.00, 3.00, and 4.00), 15 levels of decreasing disease incidence, and two confounding levels (20%, 40%) for both fixed and seasonal confounding. Each of the design-specific study samples was analyzed with a regression model. The design-specific beta; estimates were compared. RESULTS: The beta; estimates of the case-control, risk-interval, and SCCS designs were within 5% of the true risk parameters or cohort estimates. However, the case-control's estimates were less precise, less powerful, and biased by fixed confounding. The estimates of SCCS and risk-interval designs were biased by unadjusted seasonal confounding. CONCLUSIONS: All the methods were valid designs, with contrasting strengths and weaknesses. In particular, the SCCS method proved to be an efficient and valid alternative to the cohort method.

Acute Disease↗

PubMed2006

Emergency department visits among pediatric patients for sports-related injury: basic epidemiology and impact of race/ethnicity and insurance status.

OBJECTIVES: (1) To characterize the demographics and external causes of pediatric sports injury-related visits (SIRVs) to emergency departments (EDs). (2) To analyze the effect of race/ethnicity and insurance on SIRVs to EDs. METHODS: A stratified random-sample cross-sectional survey of EDs in the National Hospital Ambulatory Medical Care Survey was conducted from 1997-2001; for patients younger than 19 years, we used all visits [n = 33,654; injury-related visits (IRVs) = 13,496, SIRVs = 2990]. We examined both the external cause codes and the actual verbatim text of all IRVs. National estimates of pediatric IRVs were obtained using the assigned patient visit weights in the National Hospital Ambulatory Medical Care Survey databases and SUDAAN 9.1 software (SAS Institute, Inc., Cary, NC). RESULTS: Sports injuries resulted in 2.5 million visits annually, or 23% of ED IRVs. Male sex, older age (6-18 years), and white race/ethnicity are associated with higher rates of SIRVs. Cycling, basketball, playground injuries, and football resulted in the largest numbers of ED SIRVs. Leading diagnoses for SIRVs included fractures and dislocations, sprains and strains, open wounds, and contusions. Hispanic race/ethnicity was associated with lower rates of SIRVs across all insurance types. After controlling for demographic factors and insurance, Hispanic children were less likely to have an SIRV than white children (odds ratio, 0.7; 95% confidence interval, 0.6-0.9). CONCLUSIONS: Sports and recreation are the leading causes of pediatric ED IRVs. Hispanic children, regardless of insurance status, had lower rates of SIRVs than white children, which helps explain the lower rate of nonfatal IRVs to EDs among Hispanic youth.

Adolescent↗

PubMed2005

The essential role of generalists in health care systems.

Viewing primary care as merely one of the many niches in individual patient care fosters a narrow perspective that neither accounts for the full value of primary care nor offers proper guidance for reforming it. Instead, a systems view better articulates primary care's essential role in increasing the effectiveness and efficiency of other health care services. Primary care improves health care system functioning through such services as managing and triaging undifferentiated symptoms, matching patient needs to health care resources, and enhancing the system's ability to adapt to new circumstances. By acting as an appropriate filter for high-technology care, primary care helps ensure that it is appropriately applied, a major determinant of outcomes. Furthermore, because primary care is the most financially and geographically accessible arm of the health care system, it reduces socioeconomic and geographic disparities across the population. Even in the de facto health system that exists in the United States, these functions are necessary for the efficient, equitable, and sustainable delivery of health care and the adaptability and resilience of the system as a whole. As primary care reforms proceed, it will be important to explicitly consider how to support and strengthen its system-level benefits. Needed reforms include enabling universal access to primary care and providing the leadership, training, and infrastructure support to improve its performance as a central hub in the network of patients, clinicians, and communities. It is important that health systems realize the essential integrative function of primary care.

Health Care Reform↗

PubMed2004

Strategies to improve immunization rates and well-child care in a disadvantaged population: a cluster randomized controlled trial.

OBJECTIVE: To measure the effect of a multimodal intervention on well-child care visit (WCV) and immunization rates in an inner-city population. DESIGN: Cluster randomized controlled trial. SETTING AND PARTICIPANTS: One-year cohort of 2843 infants born at a hospital in an integrated inner-city health care system. INTERVENTIONS: Eleven clinics were randomly allocated to 1 of 3 study arms: WCV intervention (n = 3), immunization intervention (n = 4), and controls (n = 4). Interventions to improve immunization and WCV rates included both patient-based and clinic-based activities. MAIN OUTCOME MEASURES: Up-to-date status with childhood immunizations and WCVs by age 12 months (primary) and health care utilization and charges (secondary). RESULTS: Compared with the control arm, the WCV and immunization arms had 5% to 6% higher immunization rates and 7% to 8% higher WCV rates. In multivariate analyses that accounted for the clustered nature of the data, the number of immunizations received was greater in the WCV arm than in controls. However, neither the WCV nor the immunization intervention increased WCV or immunization up-to-date rates. The WCV arm had slightly higher health care charges. Neither intervention affected emergency, urgent care or inpatient utilization. CONCLUSIONS: This multimodal intervention produced a small increase in the number of childhood immunizations delivered. However, patient- and clinic-based methods did not lead to significant increases in WCV or immunization up-to-date rates after controlling for other factors. Methods found in some settings to increase immunization up-to-date rates may not be as effective in a population of inner-city socioeconomically disadvantaged children.

Child Health Services↗

PubMed2004

External causes of pediatric injury-related emergency department visits in the United States.

OBJECTIVES: To characterize the types and external causes of pediatric injury-related visits (IRVs) to emergency departments (EDs), in particular, sports-related injuries. To compare the characteristics of children with IRVs with those with non-IRVs, specifically, differences in IRV rates by race and ethnicity and by health insurance. METHODS: This was a stratified random-sample survey of EDs in the National Hospital Ambulatory Medical Care Survey (NHAMCS), including all IRVs for patients less than 19 years of age in 1998 (n = 2,656). National estimates of pediatric IRVs were obtained using the assigned patient visit weights in the NHAMCS databases and SUDAAN analyses. Measures of association between predictor variables (patient and health insurance characteristics) and whether a child had an IRV were calculated using multivariate logistic regression analyses to determine adjusted odds ratios with 95% confidence intervals. RESULTS: Pediatric IRVs accounted for more than 11 million ED visits annually. The most common diagnoses for IRVs were open wounds, contusions, sprains and strains, and fractures and dislocations. The leading external causes of IRVs were sports-related injuries, accidental falls, being struck by objects, and motor vehicle collisions. Children with IRVs differed from those who presented for non-IRVs in many characteristics: they were more likely to be male, to be older, to be of white race, and to have private insurance, and less likely to be of Asian or Hispanic ethnicity. CONCLUSIONS: Sports and recreation are the leading external causes of pediatric IRVs to EDs in the United States. There are different patterns of IRVs according to gender, age, race, ethnicity, and insurance. Identification of specific patterns of injury is necessary for the design of effective prevention strategies.

Accidents, Home↗

PubMed2003

Immunization registry accuracy: improvement with progressive clinical application.

BACKGROUND: Healthcare systems have been challenged to ensure the timely administration of immunizations. Immunization registries have been proposed to improve the accuracy and completeness of immunization information and to promote effective practice. METHODS: Comparison of randomly selected samples from two birth cohorts (1993 and 1998) from Denver Health Medical Center. Chart review and immunization registry information for these groups were compared; a composite immunization was recorded and up-to-date (UTD) status established. Registry data were compared with this composite using a sensitivity measure to assess completeness and accuracy. RESULTS: Among 818 children in the 1993 cohort and 1043 children in the 1998 cohort, there were 6386 and 6886 valid immunizations, respectively. The registry recorded 71.4% and 97.7% of these for the 1993 and 1998 cohorts, respectively (p <0.001). The apparent UTD rate, as measured with registry data alone, improved from 37% to 79% between the two time frames (p <0.001). Composite UTD status was 83.1% and 78.9% (1993 vs 1998, respectively). Accurate registry-defined UTD status improved from 44.4% to 100% between the two intervals. CONCLUSIONS: Immunization registry accuracy improved dramatically for recorded immunizations and UTD status. However, after 3 years of registry use, the overall proportion of children who were UTD had not significantly improved. The mere presence of a registry does not ensure more complete vaccination coverage. Other registry-based strategies, including use of the data for reminder, recall, and audit, may further improve immunization coverage.

Child↗

PubMed2002

Epidemiology of pediatric injury-related primary care office visits in the United States.

OBJECTIVES: Unintentional injuries are a major cause of childhood mortality and morbidity in the United States. However, there is little epidemiologic information about pediatric injuries seen in primary care settings. The objective of this study was to characterize types and external causes of childhood injuries seen by primary care physicians and to compare the demographic and visit characteristics of children with injury-related visits (IRVs) and non-IRVs. METHODS: A stratified random sample survey of office-based practicing physicians in the National Ambulatory Medical Care Survey (1997 and 1998) was conducted. Injury-related primary care office visits were measured for patients who were <19 years (number of patient visits = 6358). RESULTS: Visits for childhood injuries composed >10 million primary care office visits per year (a rate of 13.8 visits per 100 person-years). The most common diagnoses assigned to these injuries were open wounds, sprains and strains, contusions, and superficial injuries such as abrasions and splinters. Leading external causes of these injuries were sports and overexertion, accidental falls, natural factors such as bites and stings, and cutting instruments. The single most common cause of pediatric injuries was sports/overexertion. Children who had IRVs were more likely to be older (odds ratio [OR]: 1.10/year of age; 95% confidence interval [CI]: 1.08-1.12), to be male (OR: 1.5; 95% CI: 1.2-1.9), and to reside in the West (OR: 1.9; 95% CI: 1.4-2.6) or in a rural area (OR: 1.4; 95% CI: 1.1-1.9). They were less likely to be Asian (OR: 0.2; 95% CI: 0.1-0.5) or Hispanic (OR: 0.5; 95% CI: 0.3-0.8). At the visit, children with IRVs were more likely to see a physician who was not their primary care physician (OR: 1.8; 95% CI: 1.4-2.3) and to see a family physician rather than a pediatrician (OR: 2.3; 95% CI: 1.8-2.9). CONCLUSIONS: IRVs account for a significant portion of primary care for children in the United States. Identifying potentially preventable external causes of injury and characteristics of children who are more likely to be injured is important both for injury prevention programs and for the education of physicians who care for children.

Adolescent↗

PubMedDate not supplied

Individually significant risk factors do not provide an accurate clinical prediction rule for infant underimmunization in one disadvantaged urban area.

OBJECTIVE: To define a clinical prediction rule for underimmunization in children of low socioeconomic status. METHODS: We assessed a cohort of 1160 infants born from July 1998 through June 1999 at an urban safety net hospital that received primary care at 4 community health centers. The main outcome measure was up-to-date status with the 3:2:2:2 infant vaccine series at 12 months of age. RESULTS: Latino infants (n = 959, 83% of cohort) had immunization rates of 74%, at least 18% higher than any other racial/ethnic group. Multivariate logistic regression demonstrated the following independent associations (relative risk, 95% confidence interval) for inadequate immunization: non-Latino ethnicity (1.7, 1.4-2.0), maternal smoking (1.3, 1.1-1.7), no health insurance (1.9, 1.4-2.3), late prenatal care (1.9, 1.5-2.3), no pediatric chronic condition (2.1, 1.2-3.1), and no intent to breast-feed (1.3, 1.1-1.6). However, the index of concordance (c-index) for this model was only 0.69. Neither excluding infants who left the health care system nor accounting for infants who were "late starters" for their first vaccines improved the predictive accuracy of the model. CONCLUSIONS: In this predominantly Latino population of low socioeconomic status, Latino infants have higher immunization rates than other infants. However, we were unable to develop a model to reliably predict which infants in this population were underimmunized. Models to predict underimmunization should be tested in other settings. In this population, interventions to improve immunization rates must be targeted at all children without respect to individual risk factors.

Cohort Studies↗

PubMedDate not supplied

The impact of inactive infants on clinic-based immunization rates.

OBJECTIVE: Clinic-based immunization rates are used to evaluate clinic performance and immunization interventions, but they typically exclude so-called inactive patients (ie, those who no longer receive care at the clinic). We assessed the effect of enhanced ascertainment of inactive patients on clinic-based immunization rates and on the conclusions of a randomized controlled trial. METHODS: The study was a post hoc analysis of a cluster-randomized controlled trial. Infant randomization to the immunization intervention (4 clinics) or control group (4 clinics) was based on the site of their 2-week well-child care visit. The study was conducted at an integrated inner-city health care system serving a low-income population. A total of 2190 infants born between July 1, 1998, and June 30, 1999, who attended at least 1 postnatal visit, participated. In control sites, clinic staff documented inactive infants in the immunization registry and medical charts. The research staff undertook additional patient tracking efforts in the intervention clinics. RESULTS: Control clinics identified 155 (13.4%) of 1160 children as inactive within 1 year of birth, whereas 284 (27.6%) of 1030 intervention infants were documented as inactive (P < .001). In bivariate analyses from the randomized trial, immunization rates differed between intervention and control branches. In multivariate models, immunization rates were significantly higher in the intervention branch when inactive infants were removed (adjusted relative risk 1.58; 95% confidence interval, 1.28-1.89), but not when they were included (adjusted relative risk 1.09; 95% confidence interval, 0.97-1.21). CONCLUSIONS: Additional patient tracking efforts can dramatically influence inactive patient documentation and clinic-based immunization rates used for various purposes.

Ambulatory Care Facilities↗

PubMedDate not supplied

Less anticipatory guidance is associated with more subsequent injury visits among infants.

OBJECTIVE: To describe clinician delivery of injury prevention anticipatory guidance and injury visits in a birth cohort, and to describe the association of injury prevention anticipatory guidance with subsequent injury visits. METHODS: We performed a prospective cohort study of 2610 infants born from July 1, 1998 to June 30, 1999, at an urban safety-net hospital and seen subsequently for well child care (WCC, visits = 10558) and/or injury by 16 months of age. Injury guidance was defined as the proportion of recommended injury prevention anticipatory guidance items delivered to those expected, given the WCC visits the child attended. The outcome was a first injury visit to a clinic, emergency department, or hospital. RESULTS: The injury prevention items most discussed were car seats (84%-95% of all WCC visits) and rolling over at the 2-month WCC visit (80%). Other items were addressed at 36%-69% of visits. A total of 1931 (74%) of children received > or = 50% expected injury guidance. A total of 277 children (11%) had an injury visit, primarily for minor injuries. In unadjusted analysis, children receiving < 25% expected injury guidance were more likely to have a subsequent injury visit (unadjusted odds ratio 6.2; 95% confidence interval [95% CI] 3.2-9.7). In adjusted analysis, children who received < 25% and 25%-49% expected injury guidance were more likely to have a subsequent injury visits (adjusted odds ratio [AOR] 6.6; 95% CI 3.8-11.2; and AOR 2.9, 95% CI 2.0-4.3, respectively). CONCLUSIONS: Disadvantaged children whose families received less injury guidance than other children in their cohort were more likely to have a subsequent injury visit. Further studies are needed to determine whether increased injury prevention counseling reduces injury visits.

Accident Prevention↗