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Biomedical subjects

S G Humiston

Publications and source records attributed to S G Humiston.

18 recordsLinked to original sources
PubMed2000

Decline in physician referrals to health department clinics for immunizations: the role of vaccine financing.

BACKGROUND: Physicians frequently refer children to health department clinics (HDCs) for immunizations because of high out-of-pocket costs to parents and poor reimbursement for providers. Referrals for immunizations can lead to scattered care. In 1994, two vaccine financing reforms began in New York State that reduced patient costs and improved provider reimbursement: the Vaccines for Children Program (VFC, mostly for those on Medicaid and uninsured) and a law requiring indemnity insurers to cover childhood immunizations and preventive services. OBJECTIVE: To measure reported changes in physician referrals to HDCs for immunizations before and after the vaccine financing reforms. DESIGN: In 1993, a self-administered survey measured immunization referral practices of primary care physicians. In 1997, we resurveyed respondents of the 1993 survey to evaluate changes in referrals. SETTING/ PARTICIPANTS: Three hundred twenty-eight eligible New York State primary care physicians (65% pediatricians and 35% family physicians) who responded to the 1997 follow-up immunization survey (response rate of 82%). RESULTS: The proportion of physicians reporting that they referred some or all children out for immunizations decreased from 51% in 1993 to 18% in 1997 (p<0.001). In 1997, physicians were more likely to refer if they were family physicians (28% vs. 13%,p<0.01), or did not obtain VFC vaccines (29% vs. 13%,p<0.001). According to physicians who referred in 1993, decreased referrals in 1997 were due to the new insurance laws (noted by 61%), VFC (60%), Child Health Plus (a statewide insurance program for poor children, 28%), growth in commercial managed care (23%), Medicaid managed care (19%), and higher Medicaid reimbursement for immunizations that is due to VFC (18%). For physicians noting a decline in referrals, the magnitude of the decline was substantial-60% fewer referrals for VFC-eligible patients and 50% fewer for patients eligible under the new insurance law. CONCLUSIONS: Vaccine financing reforms decreased the proportion of physicians who referred children to HDCs for immunizations, and may have reduced scattering of pediatric care.

Adult↗
PubMed2000

Impact of vaccine financing on vaccinations delivered by health department clinics.

OBJECTIVES: This study measured the number of childhood vaccinations delivered at health department clinics (HDCs) before and after changes in vaccine financing in 1994, and it assessed the impact of changes in financing on HDC operations. METHODS: We measured the number of vaccination doses administered annually at all 57 HDCs in New York State between 1991 and 1996, before and after the financing changes. Interviews of HDC personnel assessed the impact of financing changes. A secondary study measured trends in Pennsylvania and California. RESULTS: HDC vaccinations for preschool children in New York State declined slightly prior to the financing changes (6%-8% between 1991 and 1993) but declined markedly thereafter (53%-56% between 1993 and 1996). According to nearly two thirds of New York State's HDCs, the primary cause for this decline was the vaccine-financing changes. HDC vaccinations for preschool children in Pennsylvania declined by 12% between 1991 and 1993 and by 56% between 1993 and 1997. HDC vaccinations for polio-containing vaccines in California declined by 31% between 1993 and 1997. CONCLUSIONS: Substantially fewer vaccinations have been administered at HDCs since changes in vaccine financing, thereby keeping preschool children in their primary care medical homes.

Adolescent↗
PubMed1999

A randomized study of tracking with outreach and provider prompting to improve immunization coverage and primary care.

OBJECTIVE: To compare and measure the effects and cost-effectiveness of two interventions designed to raise immunization rates. SETTINGS: Nine primary care sites serving impoverished and middle-class children. SUBJECTS: Complete birth cohorts (ages 0 to 12 months; n = 3015) from these sites. INTERVENTIONS: Two 18-month duration interventions: 1) tracking with outreach [tracking/outreach] to bring underimmunized children to their primary care provider office, and 2) a primary care provider office policy change to identify and reduce missed immunization opportunities (prompting). DESIGN: Randomized, controlled trial, randomizing within sites using a two-by-two factorial design. Subjects were allocated to one of four study groups: control, prompting only, tracking/outreach only, and combined prompting with tracking/outreach. Outcomes were obtained by blinded chart abstraction. MEASURES: Immunization status for age; number of days of delay in immunization; primary care utilization; and rates of screening for occult disease. RESULTS: Out of 3015 subjects, 274 subjects (9%) transferred out of the participating sites or had incomplete charts and were excluded. The 2741 (91%) remaining subjects were assessed. At baseline, study groups did not differ in age, gender, insurance type, or immunization status. Of the remaining subjects, 63% received Medicaid. Final series-complete immunization coverage levels were: control, 74%; prompting-only, 76%; tracking/outreach-only 95%; and combined tracking/outreach with prompting, 95%. Analysis of variance showed that: 1) tracking/outreach increased immunization rates 20 percentage points; 2) tracking/outreach decreased mean immunization delay 63 days; 3) tracking/outreach increased mean health supervision visits 0.44 visits per child; 4) tracking/outreach increased mean anemia screening 0.17 screenings per child and mean lead screenings 0.12 screenings per child; 5) impact of tracking/outreach was greatest for uninsured and impoverished patients; and 6) the prompting intervention had no impact on the studied outcomes, and its failure was caused by inconsistent use of prompts and failure to vaccinate ill children when prompted. Using tracking/outreach, the cost per additional child fully immunized was $474. Each $1000 spent on the tracking/outreach intervention resulted in: 2.1 additional fully vaccinated children and 668 fewer child-days of delayed immunization; 4.6 additional health supervision visits and 5.9 additional other visits to the primary care provider; and 1.8 additional anemia screenings and 1.3 additional lead screenings. CONCLUSIONS: Outreach directed toward children not up-to-date on immunizations improves not only immunization status, but also health supervision visit attendance and screening rates. The cost per additional child immunized was high, but should be interpreted in view of the spillover benefits that accompanied improved immunization. Effective means to improve coverage by reducing missed immunization opportunities still need to be identified.

Analysis of Variance↗
PubMed1997

Effect of 2 urban emergency department immunization programs on childhood immunization rates.

BACKGROUND: Emergency departments (EDs) are recommended as sites for immunizing children. However, there is little information about the effect of ED immunization programs on immunization rates. OBJECTIVES: To assess the ability of 2 ED immunization programs to vaccinate children and to measure the effect of the programs on immunization rates after the ED visit and 6 months later. DESIGN: A prospective cohort study. Emergency department patients were screened for immunization status, and vaccinations were offered to patients who either were documented to be eligible or were eligible by age and had no documented records. A systematic, sequential sample of those accepting vaccinations (study patients) was compared with a systematic, sequential sample of those not vaccinated (control subjects). Telephone interviews and medical record reviews were performed 6 months after the ED visit to verify dates of immunizations. Results were weighted to reflect the sampling frames of patients screened by the 2 programs. SETTING: Two EDs in New York City (in Manhattan and the Bronx) and the surrounding primary care offices. PATIENTS: Children (aged 0-6 years) screened for immunization status by the ED immunization program during a 10-week period; these included 210 children from the Manhattan ED (106 vaccinated in the ED) and 274 children from the Bronx ED (129 vaccinated in the ED). INTERVENTION: Emergency department immunizations. MAIN OUTCOME MEASURES: Proportion of patients (vaccinated, not vaccinated, and ED population) up-to-date for immunizations (1) at the time of the ED visit, (2) 1 day later, and (3) 6 months later. RESULTS: Two thirds of the patients in each ED had Medicaid, and one tenth were uninsured. At the time of the ED visit, 20% of the vaccinated children in each ED were actually up-to-date and were unnecessarily vaccinated; 74% (Manhattan ED) and 72% (Bronx ED) of the not vaccinated children were up-to-date (the remainder were later determined to have been eligible for vaccinations). One day after the ED visit, and 6 months later, the immunization rates of the vaccinated and not vaccinated children were similar. The results of the weighted analysis were as follows: for the entire ED population screened for immunization status, compared with up-to-date rates at the time of the ED visit, rates 1 day later were 11% (Manhattan ED) and 8% (Bronx ED) higher in each ED (P < .05); and rates 6 months later were the same in the Manhattan ED and 10% lower in the Bronx ED (P < .01). Eighteen percent of all children screened for immunization status were vaccinated; 10 to 15 children were screened and 2 to 4 children were vaccinated per 8-hour ED shift. CONCLUSIONS: This ED immunization program temporarily improved the immunization rates of the ED population, but substantial personnel time was required to achieve these small gains. Urban ED immunization programs are unlikely to be cost-effective.

Child↗
PubMed1996

Reducing missed opportunities for immunizations. Easier said than done.

BACKGROUND: Missed opportunities for immunizations are associated with underimmunization of preschool-age children. Practice policies limiting immunizations to scheduled preventive visits and guidelines requiring legal guardians to sign consent forms for vaccinations are 2 factors contributing to missed opportunities. However, methods to change these policies have not been sufficiently evaluated. OBJECTIVE: To measure the effectiveness of (1) changing practice policies to incorporate the new national standard to screen and vaccinate eligible children at all office visits and (2) eliminating legal guardian signature requirements. DESIGN: A randomized controlled trial of 2 interventions: (1) changing practice policy and routine to have office nurses screen for immunization status at all visits, attach immunization reminder cards to medical charts for eligible patients, and have providers vaccinate eligible children ("no missed opportunities" intervention) and (2) changing practice guidelines to allow vaccinations without a legal guardian's signature. The first intervention was performed at both sites; the second only at the neighborhood health center (NHC). SETTING: A Pediatric Continuity Clinic in a teaching hospital (hereafter referred to as Clinic), and an NHC. PATIENTS: Enrolled in the trial were 1005 Clinic patients and 983 NHC patients, 0 to 2 years of age. MAIN OUTCOME MEASURES: Missed opportunity rates, immunization rates, and rates of preventive services. RESULTS: Eliminating the requirement for a legal guardian's signature had no effect on any of the outcome measures. The no missed opportunities intervention was partially effective. Study patients had slightly fewer missed opportunities than control patients at each site: (0.60 vs 0.90 per patient per year at the Clinic, P = .01; 1.1 vs 1.3 per patient per year at the NHC, P = .02). For study group patients, immunization reminder cards were attached to medical charts in only one third of vaccine-eligible visits; when attached, they markedly increased vaccination by providers (odds ratio for vaccinating at a visit was 6.9 comparing visits when immunization reminder cards were attached vs not attached). However, at the end of the study, immunization rates were similar for study and control groups at each site. The number of undervaccinated days was slightly lower for the no missed opportunities study group at the Clinic than for the control group (56 days vs 77 days, P < .001), but they were similar for both groups at the NHC. There were no differences in rates of preventive visits or screening tests between study and control groups. CONCLUSIONS: The interventions evaluated to reduce missed opportunities did not increase immunization rates. The key problem was failure to screen for immunization status at all visits. More effective interventions will be needed to overcome barriers within busy primary care practices to substantially reduce missed opportunities.

Female↗
PubMed1996

Effect of emergency department immunizations on immunization rates and subsequent primary care visits.

BACKGROUND: The Standards for Pediatric Immunization Practices recommend the routine use of emergency department (ED) encounters for screening the immunization status of children and, if indicated, immunizing them. OBJECTIVE: To test the hypothesis that ED immunizations will improve immunization rates without decreasing subsequent primary care visits. DESIGN: A randomized controlled trial of 2 interventions. Children (aged 6-36 months) (n = 1835) were enrolled in the study in the ED; informed consent was obtained from their parents. They were randomized into 1 of 3 groups: (1) the control group (n = 614), in which no intervention was undertaken; (2) the letter group (n = 610), in which a letter to the primary care physician was written indicating the child's estimated likelihood of being underimmunized; and (3) the ED vaccination group (n = 611), in which, based on a decision rule, those likely to be underimmunized were offered immunizations in the ED. After randomization, parents were interviewed in the ED using a decision rule to estimate the likelihood of the child being underimmunized. One year after enrollment in the study, the medical records of the children at their primary care sites were reviewed to determine the immunization status of the children and primary care use patterns. SETTING: An urban ED and 54 primary care sites in Monroe County, New York. RESULTS: The mean age of the participants was 17.9 months. Medical record review-verified underimmunization rates at the time of the ED visit were 33%, 31%, and 28% for the control, letter, and ED vaccination groups, respectively. The demographic characteristics and baseline immunization rates were not different among study groups. According to the decision rule, 248 children (41%) in the ED vaccination group were likely to be underimmunized. Parents of these 248 children were offered immunizations for their children; 117 (47%) accepted, and their children were immunized (with 230 separate immunizations). One month after the ED visits, the underimmunization rates of the study groups were 31%, 28% (P = .40 compared with the control group), and 23% (P = .002). One year later, these rates were 28%, 25% (P = .20), and 25% (P = .20). No clinically meaningful differences were present at either of these times. One year after the ED visit, no differences in the rates of primary care use were found among groups. CONCLUSIONS: This study provides evidence that the immunization of children in this ED was ineffective at raising their immunization rates; primary care attendance was also unaltered. Major obstacles were as follows: (1) an inability to ascertain accurately the immunization status in the ED and (2) a high rate of parental refusal to accept immunizations in the ED. The standards should be modified to de-emphasize the ED as a routine immunization site for children with access to primary care. Efforts and resources should be directed toward strengthening the primary care system and tracking immunization status.

Child, Preschool↗
PubMed1995

Is underimmunization a marker for insufficient utilization of preventive and primary care?

OBJECTIVE: To test the hypothesis that the underimmunization of young children is a marker for the lack of preventive and acute primary care. SETTING: Primary care center serving an impoverished population (90% Medicaid). DESIGN: Historical cohort study (N = 1178) of children aged 12 to 30 months that determined each child's immunization status, anemia, tuberculosis, and lead screening status; and office utilization history. Screening delay was defined as missing a recommended screening by more than 3 months past the standard screening age. RESULTS: Thirty-four percent of the population were underimmunized at 12 months of age. Compared with fully immunized children, these children were at greater risk for screening delay: anemia, 38% vs 5% (risk ratio [RR], 7.5; 95% confidence interval [CI], 5.4 to 10.4); tuberculosis, 76% vs 44% (RR, 1.7; CI, 1.6 to 1.9); and lead, 69% vs 33% (RR, 2.1; CI, 1.9 to 2.4). These RRs increased with greater immunization delay. Compared with fully immunized children, the underimmunized group made 47% fewer preventive health visits (2.5 vs 4.7 visits per infant per year, P < .001) and 43% fewer illness visits (2.5 vs 4.4, P < .001) and had 50% more missed appointments (2.1 vs 1.4, P < .001). Logistic regression, predicting anemia screening delay at 12 months of age, showed that underimmunization had an effect independent of utilization, with an odds ratio of 7.7 (CI, 5.2 to 12.0). CONCLUSION: Underimmunization was a powerful, independent marker for inadequate health supervision in this population. IMPLICATIONS: The current emphasis on immunizations has the benefit of targeting children at risk of lack of preventive and acute care. Improving immunization rates may have the potential to improve other aspects of primary care if immunization provision is not uncoupled from primary care.

Child Health Services↗
PubMed1995

Physician and parent opinions. Are children becoming pincushions from immunizations?

OBJECTIVE: To determine parent and physician opinions regarding the administration of multiple childhood immunizations by injection. DESIGN: Confidential mailed survey to physicians and residents; interview of parents during office visits for immunizations. PARTICIPANTS: Physicians and parents from Rochester, NY. RESULTS: The survey included 215 practicing physicians and 74 residents; response rate was 82%. Of the 197 parents interviewed, 93% were mothers, 68% were white; the mean (+/- SD) age was 25.8 +/- 5.2 years, with 12.8 +/- 1.8 years of education; 59% had private insurance, and 35% had Medicaid coverage. Of the parents, 31% had strong concerns about their child receiving a single injection; an additional 10% (total, 41% vs 31%; chi 2 = 4.05, P = .04) had the same concerns about their child receiving three injections. More practicing physicians than parents had strong concerns about children 7 months old or younger receiving three injections (60% vs 41%; chi 2 = 7.71, P < or = .01). Physician concern increased further when physicians were asked about administration of four injections (80% vs 60%; chi 2 = 18.77, P < .001). Of the parents, 64% preferred one rather than two visits to have three injections administered, if their physician recommended it; 58% still preferred one visit even if four injections were needed. CONCLUSIONS: Physicians have more concerns than parents about the administration of multiple injections at a single visit. Pain for the child was the main concern of all respondents. While most physicians have strong concerns about administering three or more injections at one visit, most parents prefer this practice. Continued education and reassurance of parents and physicians is needed to address concerns about children becoming "pincushions" from immunizations.

Adult↗
PubMed1994

Immunization practices of primary care practitioners and their relation to immunization levels.

OBJECTIVES: To assess variations in immunization practices and attitudes among primary care providers and to relate these characteristics to the immunization levels of their patients. SETTING: Monroe County, New York. DESIGN: Survey of pediatricians (n = 96) and family practitioners (n = 44) to assess immunization practices and attitudes and medical chart reviews for 1884 patients of 32 physicians who practice in the city of Rochester to measure immunization levels. ANALYSIS: Tabular analyses for survey responses (chi 2 test and Fisher's Exact Test); logistic regression to assess the relation between provider responses and measured immunization levels. RESULTS: Responses by pediatricians and family practitioners were similar. Most providers did not routinely immunize during acute-illness visits but did immunize during follow-up or chronic-illness visits. Few used tracking systems to identify underimmunized children. Most practitioners immunized children who had colds but withheld immunizations from children who had fevers or otitis media. Most providers agreed with expanding immunization programs to include sick visits, health department clinic visits, and community site visits, but most thought that they should not be provided at emergency department visits, except for very-high-risk children. Immunization levels at 10 months of age were positively correlated with private practice setting (P = .001) but negatively correlated with immunizing at acute- (P < .01) or chronic-illness (P < .05) visits, Medicaid coverage (P < .05), and high rates of appointments that were not kept (P < .001). CONCLUSIONS: Primary care providers' immunization practices and attitudes vary and do not always follow established guidelines for immunization delivery. Many providers of high-risk children are already attempting to improve immunization delivery by using patient reminders and by immunizing children at acute- or chronic-illness visits. Improving provider immunization practices to deliver childhood immunizations more effectively must be part of our efforts to resolve this nation's childhood immunization problem.

Adolescent↗
PubMed1994

Intent to immunize among pediatric and family medicine residents.

OBJECTIVE: To determine whether contraindications to immunization are inappropriately broadened for children with a fever or a neurologic condition. PARTICIPANTS: Pediatric and family medicine residents (N = 52 and 23, respectively) at the University of Rochester (NY). DESIGN: Cross-sectional survey. Residents rated how likely they would be to administer a diphtheria-tetanus-pertussis or measles-mumps-rubella vaccine in 17 clinical scenarios according to a rating scale ranging from 1 (never) to 5 (always). For all scenarios, the immunization was recommended by the American Academy of Pediatrics or the Immunization Practices Advisory Committee. RESULTS: In only five and three of 17 scenarios would 90% or more of the pediatric residents and family medicine residents, respectively, have administered an immunization. For diphtheria-tetanus-pertussis vaccine, pediatric residents reported a lower likelihood of vaccinating a 2-month-old child with a low fever (temperature, 38.1 degrees C) than an afebrile child (mean score, 3.0 vs 4.7; P < .01). A 2-year-old child with idiopathic epilepsy, a 2-month-old child with intraventricular hemorrhage, and a 2-month-old child who had a parent with a seizure disorder each had a lower reported likelihood to be vaccinated than a same-aged child without a neurologic condition (2.8 vs 4.5; 4.1 vs 4.7; and 4.3 vs 4.7, respectively; each P < .01). For measles-mumps-rubella, pediatric residents reported a lower likelihood of vaccinating a 15-month-old child with a low fever than an afebrile child (4.2 vs 4.9; P < .01). A child with a progressive neurologic disease had a lower reported likelihood to be vaccinated than a child without a neurologic condition (3.5 vs 4.9; P < .01). CONCLUSIONS: Residents reported a lower likelihood of immunizing children with a fever or neurologic condition. Such practice styles may contribute to underimmunization. Residents need to be educated regarding which medical conditions contraindicate an immunization.

Attitude of Health Personnel↗
PubMed1994

Immunization practices of pediatricians and family physicians in the United States.

OBJECTIVE: To assess current practices and attitudes among pediatricians and family physicians across the United States regarding immunizations. DESIGN: Survey of a random sample of pediatricians and family physicians. SUBJECTS: Fellows of the American Academy of Pediatrics (N = 746) and American Academy of Family Medicine (N = 429). SURVEY TOPICS: General immunization practices (eg, types of visits during which vaccinations are provided, mechanisms to identify undervaccinated children); and opinions about perceived barriers to immunizations, acceptance of alternative sites for immunizations, and possible immunization requirements for Medicaid and The Special Supplemental Food Program for Women, Infants, and Children (WIC). RESULTS: Pediatricians and family physicians (combined) reported the following: immunizing children during acute illness visits (28%), follow-up visits (90%), and chronic illness visits (77%); using computer or reminder files to identify undervaccinated children (13%); and simultaneously administering four vaccines (diphtheria-tetanus-pertussis, oral poliovaccine, measles, mumps, and rubella and Haemophilus influenzae type b) to an eligible 18-month-old child (66%). Physicians perceived the following as barriers to immunizations: missed preventive visits (40%), vaccine costs (24%), lack of insurance coverage (24%), inability to track undervaccinated patients (22%), incomplete immunization records (12%), and missed vaccination opportunities (12%). Physicians agreed with offering vaccinations during hospitalizations (51%) or emergency department visits (30%), and with immunization requirements for continued eligibility for Medicaid (66%) or WIC (64%). Pediatricians were more likely to vaccinate during chronic illness and follow-up visits, and were more likely to use systems to track undervaccinated children (P < .05); however, most immunization practices and attitudes of pediatricians and family physicians were similar. Physicians who graduated from medical school more recently and those in high-risk urban practices were more likely to vaccinate during acute illness visits, provide simultaneous vaccinations, and favor vaccinations in hospital settings. CONCLUSIONS: Vaccination rates might be improved by closer adherence to current immunization guidelines regarding vaccinations during all encounters and simultaneous vaccinations, by developing systems to identify undervaccinated children, and by reducing patient costs for vaccinations. Current immunization practices fall short of the immunization guidelines; changes in individual practice styles will be required to conform with these standards.

Acute Disease↗
PubMed1993

Decision rules for predicting vaccination status of preschool-age emergency department patients.

We produced and tested rules to predict undervaccination among preschool-age emergency department (ED) patients. Data were gathered on demographics, vaccination status, health status, and health care utilization from parents, ED physicians, and ED charts at an urban teaching hospital in Rochester, N.Y. Primary care charts were reviewed to verify vaccination status. Using recursive partitioning, we developed decision rules to predict undervaccination. Decision rules were developed on a sample of 602 ED patients 4 to 48 months of age and then prospectively tested on 1832 ED patients aged 6 to 36 months. Factors associated with undervaccination for any vaccine included parental report of vaccination delay (odds ratio = 8.1; p < 0.001), inability to report the receipt of the appropriate number of vaccines (odds ratio = 4.5; p < 0.001), lack of health insurance (odds ratio = 3.6, p < 0.001), elapsed time since the last visit to primary care provider (p < 0.001), household size (p < 0.001), and maternal age (p < 0.01). Eight decision rules were produced that varied in their number of questions (one to six), sensitivity (0.27 to 0.87), and specificity (0.54 to 0.98). No single rule was both highly sensitive and highly specific. The rules' sensitivities and specificities were similar for the validation sample of 1832 patients. Thus a decision rule could not be produced that was both sensitive and specific. Identification of undervaccinated children by means of information available at an ED visit is inherently difficult. Interventions in the ED may be inefficient unless better methods of assessing vaccination status can be developed.

Child↗
PubMed1993

The school-based immunization survey: an inexpensive tool for measuring vaccine coverage.

A school-based immunization survey was conducted among the 36 Rochester, NY, elementary schools (n = 5584 children) to determine (1) the vaccination rates at 2 years of age by type of primary care provider and (2) the accuracy of school immunization records (by comparing them with medical charts for children attending hospital-based clinics). These rates varied by provider type from 58% to 86% and were all below the national goal of 90%. In comparison with medical chart review, the school data had error rates of 15%; however, these errors occurred in both directions and were thus unbiased. School-based surveys include children who lack connections to the primary care system. With minimal effort these surveys can help identify populations in need of intervention.

Bias↗
PubMed1993

Missed opportunities for childhood vaccinations in office practices and the effect on vaccination status.

To determine the rate of childhood under-vaccination, rate and types of missed opportunities (MOs) for vaccinations, and the contribution of MOs to the undervaccination of preschool-age children, the authors conducted a retrospective medical chart review in seven primary care settings in the Rochester, NY, area: a hospital clinic, a neighborhood health center, a group-model health maintenance organization, an urban group practice, a suburban group practice, a rural health center, and a rural private practice. The random sample included 1124 children having birth dates between March 15, 1988, and September 15, 1989. The main outcome measures were cumulative undervaccination rate, defined as the proportion of patients from each practice who were ever > 60 days past-due for a vaccination by 12, 18, or 24 months of age; undervaccination time, defined as the median number of months during which children were undervaccinated; number of MOs; visit types and conditions associated with the MOs; and the duration of undervaccination time attributable to MOs. The cumulative undervaccination rate by 12 months was at least 20% in each practice except for the suburban practice, where it was 4%. The frequency of MOs varied from a high of 1.8 MO per patient per year at the rural private practice to a low of 0.3 MO per patient per year at the suburban practice. More than one quarter of MOs occurred during either health supervision or follow-up visits in all practices. In 28% of visits during which an MO occurred, patients had no fever or acute illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Child Health Services↗
PubMed1993

Is an emergency department visit a marker for undervaccination and missed vaccination opportunities among children who have access to primary care?

The purpose of this study was to determine: (1) whether preschool-age patients who utilize the emergency department (ED) are undervaccinated compared with patients having the same primary care provider and (2) whether reducing missed vaccination opportunities in the primary care office can potentially reduce the differences in undervaccination between the groups. This retrospective cohort study involved two groups: 583 ED patients, aged 4 to 48 months, who had primary care providers; and 583 control subjects randomly selected from primary care sites and matched according to date of birth and primary care site. The major outcome variable was the point prevalence of undervaccination, defined as more than 60 days past due for a vaccine at the time of the ED visit, and for control subjects, at the time of their matched patient's ED visit. Demographic variables, vaccination history, presence of chronic illness, and office utilization history were abstracted from office charts. The mean age of all patients was 20.0 months. Emergency department patients were more likely to be boys (61% vs 50%) and had more chronic illness, but did not differ racially from those in the control group. Primary care sites included a hospital-based clinic (n = 137), neighborhood health centers (n = 172), and private practices (n = 274). The undervaccination rates by primary provider type were for (1) hospital clinic ED patients 21.1%, control subjects 19.7%; (2) neighborhood health center ED patients 29.1%, control subjects 22.7%; and (3) private practice ED patients 26.6%, control subjects 14.9%. Overall, the odds ratio of ED patients' being undervaccinated compared with control subjects was 1.8 (95% confidence interval 1.3 to 2.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMedDate not supplied

ROC curves for classification trees.

A common problem in medical diagnosis is to combine information from several tests or patient characteristics into a decision rule to distinguish diseased from healthy patients. Among the statistical procedures proposed to solve this problem, recursive partitioning is appealing for the easily-used and intuitive nature of the rules it produces. The rules have the form of classification trees, in which each node of the tree represents a simple question about one of the predictor variables, and the branch taken depends on the answer. The authors consider the role of misclassification costs in developing classification trees. By varying the ratio of costs assigned to false negatives and false positives, a series of classification trees are generated, each optimal for some range of cost ratios, and each with a different sensitivity and specificity. The set of sensitivity-specificity combinations define a curve that can be used like an ROC curve.

Child, Preschool↗