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Biomedical subjects

K M McConnochie

Publications and source records attributed to K M McConnochie.

35 records · Page 2Linked to original sources

Hospitalization for lower respiratory tract illness in infants: variation in rates among counties in New York State and areas within Monroe County.

OBJECTIVE: Lower respiratory tract illness (LRI) is the most common serious illness in childhood and the most common reason for hospitalization of infants beyond the neonatal period. This study assessed the potential for cost savings from reduction in hospitalization for LRI. SETTING AND SAMPLE: LRI hospitalization rates for children in the first 2 years of life (infants) were studied for the 62 counties of New York State and six socioeconomic areas within Monroe County (Rochester) for the years 1985 through 1991. DESIGN: Analysis of small area variations. RESULTS: LRI accounted for 51.2% of infant hospitalizations in New York State. The overall LRI hospitalization rate for New York's 62 counties was 27.0 per 1000 child-years and ranged, among the 18 most populous counties, from 10.7 for Monroe County to 39.3 for the Bronx. Unemployment rate was the strongest predictor of LRI hospitalization rates for counties, explaining 29% of the variance in multiple regression analysis. Within Monroe County, LRI hospitalization rates followed a geographic gradient from the inner city (22.5) to the rest of the city (12.2), and to the suburbs (7.3). Deaths from LRI were uncommon (0.36% of state LRI hospitalizations) and varied little between inner city (0.42%) and suburbs (0.51%). If LRI hospitalization rates for Monroe County suburban children prevailed for the entire state, 10,439 hospitalizations and $32,916,000 would be saved annually. CONCLUSIONS: A large portion of the increased cost of health care for children living in poverty is attributable to hospitalization for LRI in infants. Physician discretion in decision making and factors associated with socioeconomic status are probably major determinants of variation. Well-coordinated follow-up of acute illness visits, home monitoring by visiting nurses, and empirically based clinical guidelines for management of LRI might yield both substantial cost savings and better service to families.

Costs and Cost Analysis↗

Lead screening among high-risk urban children. Are the 1991 Centers for Disease Control and Prevention guidelines feasible?

OBJECTIVE: To determine whether the 1991 Centers for Disease Control and Prevention lead poisoning prevention guidelines for biannual screening and retesting are feasible among a high-risk population. METHODS: For 632 urban high-risk children aged 9 to 25 months who used a pediatric primary care center between 1989 and 1991, we assessed physician screening practices and the need to increase utilization to meet guidelines for retesting. Analysis also focused on missed opportunities for lead screening. For 425 urban high-risk children who were long-term utilizers of the center, we assessed the need to increase utilization to meet guidelines for biannual screening. RESULTS: Screening was not up to date in 55%, 34%, and 29% of children at ages 9 to 13 months, 14 to 19 months, and 20 to 25 months, respectively. These children had a mean of 2.3, 2.5, and 2.3 missed opportunities during each age period. Among children who had made well-child visits, in 41%, 36%, and 28% of children screening was not up to date at each age period. Between ages 13 and 37 months, 42% of long-term clinic utilizers made sufficient visits to achieve biannual screening. Sixty-five percent of children who were screened made a subsequent visit within 2 to 5 months, at which time retesting could have been performed. CONCLUSIONS: At this primary care center, many high-risk children, including those who had made well-child visits, were not appropriately screened for lead toxic effects. Children not screened had many missed opportunities at all types of visits, including well-child visits. Many children visited frequently enough to achieve biannual screening and retesting without increased numbers of visits if non-well-child visits had been used as opportunities for retesting.

Centers for Disease Control and Prevention, U.S.↗

Immunization opportunities missed among urban poor children.

Low immunization rates among US preschool children suggest a need for improved immunization practices. Immunization and encounter records were reviewed to ascertain immunization rates and missed opportunities for vaccine administration among 515 preschool children who were active patients at a hospital-based primary care center serving lower socioeconomic status families in Rochester, NY. The point prevalence at a mean age of 4.4 years for lack of one or more recommended immunizations was 27%; 7% were missing measles-mumps-rubella, 18% were missing Haemophilus influenzae type b, 8% were missing two or more diphtheria-tetanus-pertussis, and 4% were missing two or more oral poliovirus immunizations. A visit was counted as a missed opportunity if an immunization was due but not given. Over the period from birth through age 36 months, 422 (82%) of children missed at least one immunization opportunity. For these 422 children, there was a mean of 7.2 missed opportunities per child. Although 64% of missed opportunities occurred at an acute illness visit, 36% occurred at well-child, administrative, follow-up, or chronic illness visits. Review of 200 medical records randomly selected from all opportunities at acute illness visits found no contraindication in 63% (50% nonfebrile infectious disease, 13% minor noninfectious problems). Findings for random samples of 100 missed diphtheria-tetanus-pertussis opportunities for children aged 2 to 6 months and 100 missed measles-mumps-rubella opportunities for children 15 to 24 months were similar to findings for the sample of all acute illness visits. Emergency department visits, where immunization records were not readily available, accounted for 18% of missed opportunities.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗

Variation in severity of respiratory syncytial virus infections with subtype.

Two major subtypes of respiratory syncytial virus have been identified. This study assessed the hypothesis that A-subtype infections were more severe than B-subtype infections among the 157 infants hospitalized in two hospitals in Rochester, N.Y., during two winters. Severity was measured both by specific clinical observations and by a severity index that was derived empirically. Among all subjects, several clinical observations suggested that A-subtype infections were more severe. For example, mechanical ventilation was required in 12.6% of those with A-subtype compared with 1.6% of those with B-subtype infection (relative risk = 7.88; p = 0.01). Among high-risk infants (infants with underlying conditions or age 3 months or less at admission), carbon dioxide tension greater than 45 mm Hg was found in 37.0% of those with A-subtype compared with 12.0% of those with B-subtype infection (relative risk = 3.08; p = 0.04). In discrete multivariate (logit) analysis, effects of subtype (odds ratio = 6.59; p less than 0.01) on severity remained after adjustment for other statistically significant effects of age less than 3 months, underlying condition, and premature birth. The finding that A-subtype infections were more severe might have important implications for vaccine development, studies of the virulence of respiratory syncytial virus, clinical management (e.g., selection for antiviral therapy), and long-term prognosis.

Age Factors↗

Occurrence of groups A and B of respiratory syncytial virus over 15 years: associated epidemiologic and clinical characteristics in hospitalized and ambulatory children.

Over 15 years respiratory syncytial virus (RSV) isolates from 1209 hospitalized and ambulatory children were examined for strain group and in a subset for subgroup to determine the associated epidemiologic and clinical characteristics. Three patterns of yearly outbreaks existed: (1) strong predominance of group A strains (9 years with 83%-100% A strains), (2) relatively equal proportions of group A and B strains (4 years), and (3) strong predominance of group B strains (78%-85%) in 2 years, separated by a decade. The first pattern of highly dominant A strains occurred in cycles of 1 or 2 consecutive years with a single intervening year in which B strains were greater than or equal to 40% of the isolates. Subgroups A1 and A2 predominated, while B2, 3, and 4 occurred almost equally. A greater clinical severity for Group A strains was suggested by children with group A infections requiring intensive care significantly more often (15.4 vs. 8.3%, P = .008). Further, strongly dominant A strain years were associated with higher proportions of RSV admissions requiring intensive care (16.6% vs. 5.5%, P less than .01). Strains of subgroups A2 and B4 were more frequently found in hospitalized patients and A1 in outpatients, and the 2 years with the highest rates of intensive care admissions were those in which subgroup A2 dominated.

Age Factors↗

Prediction rules for selective radiographic assessment of extremity injuries in children and adolescents.

To assess the potential for selective use of roentgenography in evaluating extremity injuries, prediction rules were developed based on prospective observations for 617 injured children and adolescents examined in our Emergency Department (phase 1) and tested on 601 examined 1 year later (phase 2). Logit analysis produced best-fitting statistical models for phase 1 data with significant (P less than 0.05) direct effects of gross signs, point tenderness, activity not routine, swelling moderate or severe, time from injury less than 6 hours, and pain with motion for upper extremity injuries; and, for lower extremity injuries, not knee injury, activity not routine, point tenderness, and foot injury. Prediction rules developed in phase 1 performed equally well when tested on phase 2 injuries. Data from both phases were combined, therefore, in analysis that produced risk estimates. For all injury types (ie, for injuries with all possible combinations of presence or absence of these findings), risk for fracture was derived. For upper extremity injuries, with a threshold risk for fracture of 20% used to select specific injury types for roentgenography, prediction rule outcomes were 18.1% of roentgenograms avoided and 5.3% of fractures missed. For lower extremity injuries, using a threshold risk of 10% to select injury types for roentgenography, outcomes were 25.8% of roentgenograms avoided and 5.3% of fractures missed. Alternative prediction rules allowed still greater roentgenogram avoidance, although missed fractures also increased. Risk of adverse functional outcome from missed fractures appeared small. Annual national cost savings from the elimination of 18.1% of upper and 25.8% of lower extremity roentgenographic evaluations was estimated at $103 million.

Adolescent↗

Wheezing at 8 and 13 years: changing importance of bronchiolitis and passive smoking.

A group of 153 children (51 with a history of bronchiolitis and 102 matched controls) were evaluated in a historical cohort study at a mean age of 8 years and again at 13 years to test the primary hypothesis that mild bronchiolitis, far more common than severe (hospitalized) bronchiolitis, predicts wheezing. A secondary hypothesis was that passive smoking also predicts wheezing. Many potentially confounding variables such as family history of asthma were controlled in analyses. Analysis at 13 years produced results that were not anticipated from previous analysis of interviews at age 8. Although mild bronchiolitis was a powerful predictor of wheezing at age 8 years, it was no longer a strong predictor of wheezing at age 13 in either bivariate or multivariate analysis. Although epidemiologic studies, by their nature, cannot prove causality, findings are consistent with the hypothesis that sequelae often follow mild bronchiolitis but diminish during childhood. Maternal smoking was a powerful predictor of wheezing at age 13 in bivariate analysis (Kendall's Tau B = 0.19, P less than 0.01) and in multivariate analysis (odds ratio = 2.67, P less than 0.01). In children at highest risk for wheezing, males with a family history of asthma, multivariate analysis suggested that maternal smoking is associated with an increase in wheezing from 36% to 60%. We conclude that passive smoking, previously identified as a risk factor in this population for both bronchiolitis in infancy and wheezing at age 8, is a risk factor for wheezing-associated morbidity throughout the childhood years.

Adolescent↗

Lower respiratory tract illness in the first two years of life: epidemiologic patterns and costs in a suburban pediatric practice.

The epidemiologic patterns and the economic impact of acute lower respiratory tract illness (LRTI) in children under age two were studied using data collected from November 1, 1971-August 30, 1975 in a suburban pediatric practice in Monroe County, New York. LRTI was responsible for 23 illness episodes per 100 child-years among children in their first two years of life. This indicates that a cohort of 100 children might be anticipated to have 46 LRTI episodes from birth until their second birthday. The majority of episodes correlated with the presence of four viruses in the community, most commonly respiratory syncytial virus. The minimal, estimated direct cost of LRTI in the first two years of life based on 1984 cost data was equivalent to $35.14 for every child and was comprised of hospitalization cost ($19.68) and ambulatory care cost ($15.46). Hospitalization costs attributable to LRTI comprised at least 2.5 per cent of all hospitalization costs in this age group. Immunization against the four most common respiratory viruses, at a reasonable cost per child immunized, would appear to be cost beneficial.

Child↗

Parental smoking, presence of older siblings, and family history of asthma increase risk of bronchiolitis.

Bronchiolitis is a common lower respiratory tract illness in infants and has substantial acute morbidity and sequelae. To identify risk factors for bronchiolitis, a case-control study was conducted in which 53 subjects who had bronchiolitis were matched with two controls who had no bronchiolitis in infancy. In multivariate analysis, direct effects of passive smoking and older siblings achieved statistical significance. Family history of asthma appeared to interact with older siblings. Among subjects without a family history of asthma, statistically significant predictors proved to be older siblings (odds ratio, 2.31) and passive smoking (odds ratio, 3.87). Among subjects with a family history of asthma, older siblings proved to be an even stronger predictor (odds ratio, 46.81), while the odds ratio for passive smoking did not change much (odds ratio, 4.03). The combined presence of older siblings and passive smoking yielded an odds ratio of 8.94 among subjects without a family history of asthma and 181.67 among subjects with a family history of asthma. Analysis provided risk estimates that were particularly high for certain groups. Among infants with a family history of asthma, 49% who have an older sibling may develop bronchiolitis. If they are also exposed to cigarette smoke, almost 80% may develop bronchiolitis. Among infants without a family history of asthma, bronchiolitis may develop in 46% of infants if there is both an older sibling and exposure to smoke. Exposure of infants to cigarette smoke might diminish more rapidly if clinicians and parents were aware of such high risks. Efforts to reduce morbidity from bronchiolitis in infants might best be directed at the reduction of smoking in families with previous children, particularly if there is a family history of asthma, and at methods that protect infants from respiratory virus carried by siblings.

Asthma↗

Predicting clinically significant lower respiratory tract illness in childhood following mild bronchiolitis.

A historical cohort study was conducted to measure lower respiratory tract illness (LRTI) up to nine years following mild bronchiolitis and to discover attributes that predict an increased risk for LRTI in childhood. The hypothesis assessed was that the occurrence of bronchiolitis predicts LRTI following the second birthday (childhood LRTI) after adjusting for potentially confounding variables such as a family history of respiratory allergy. Fifty-three children (index subjects) who were seen for bronchiolitis at a suburban community pediatric practice were compared on the basis of childhood LRTI with a control group of 159 children. Chart review, when children were a mean of 8 years old, determined the frequency of childhood LRTI. The mean frequency of childhood LRTI was greater in index subjects than in control subjects (1.62 vs 0.98). This difference remained after adjusting for potentially confounding variables. The yearly occurrence of any LRTI was significantly more common in index subjects through the third year of life (38% vs 15%). A tendency for a more common occurrence of any LRTI was noted through the fifth year (25% vs 16%), but not thereafter. Further analysis of index subjects disclosed that only those who experienced a subsequent LRTI before the second birthday were at an increased risk for the development of childhood LRTI.

Bronchiolitis, Viral↗

Normal pulmonary function measurements and airway reactivity in childhood after mild bronchiolitis.

Concern about the long-term sequelae of bronchiolitis has been raised through studies of children hospitalized for bronchiolitis, but the long-term sequelae of mild bronchiolitis have not been studied. We assessed the hypothesis that 25 children with mild bronchiolitis (index subjects) were at greater risk for abnormalities of pulmonary function or airway reactivity to cold air between the ages of 8 and 12 years than were randomly selected, matched controls. There were no consistent differences in pulmonary function or airway reactivity between index and control groups. Airway hyperreactivity was found in five control subjects and three index subjects, and all children with symptomatic asthma were identified by cold air challenge. Our data suggest that children with a history of mild bronchiolitis are not at increased risk between ages 8 and 12 years for airway hyperreactivity or for abnormalities in pulmonary function.

Adult↗

Bronchiolitis as a possible cause of wheezing in childhood: new evidence.

A historical cohort study was performed in order to assess the hypothesis that even mild bronchiolitis in infancy in a predictor of wheezing later in childhood. Subjects who had experienced bronchiolitis and a matched control group were compared in terms of reported wheezing 8 years later. A highly significant difference was found between the bronchiolitis group and the control group in terms of current wheezing (P less than .0001, relative risk 3.24). This difference was maintained after adjusting for many potentially confounding variables including family history of allergy and other allergic manifestations in the child. Results suggested that 13.6% of a normal practice population in the age range 6 to 9 years currently wheeze, but that 44.1% of children who experienced bronchiolitis currently wheeze. Based on the incidence of bronchiolitis (4.27/100 children in their first 2 years of life) and the relative odds for wheezing derived from a logistic regression model including variables that measured passive smoking, genetic tendency to wheeze, and bronchiolitis, calculations of attributable risk suggested that wheezing in 9.4% of the population of children who currently wheeze was attributable to bronchiolitis.

Adolescent↗

The impact of a required preceptorship on senior medical students.

The impact of a required preceptorship program was measured by comparing the perceptions of senior medical students who would have elected the preceptorship rotation had it not been required (the elective group) and those who participated only to fulfill the requirement (the required group). The main difference between the two groups before the preceptorship was the elective group's career preference for family medicine and the required group's preference for an internal medicine subspecialty. The preceptorship had no impact for either group on inclinations toward other specialties, preferred practice setting, or assessment of practice location determinants. Both groups, however, perceived an increase in knowledge of primary care practice and confidence in relevant clinical skills following the preceptorship. These results are used to support the value of a required preceptorship program.

Attitude↗

Airway hyperreactivity and a history of clinical manifestations of asthma in childhood.

The relationship between airway hyperreactivity and a history of the clinical manifestations of asthma was investigated in 54 children between the ages of 8 and 12. Airway reactivity was assessed by measuring the change in pulmonary function following the hyperventilation of subfreezing air. Clinical manifestations of asthma were assessed by a standardized questionnaire regarding lower respiratory symptoms and by medical records review. The subjects were participating in a study of the sequelae of bronchiolitis; 25 had seen a physician for mild bronchiolitis during the first 2 years of life, and the remainder had not. Airway hyperreactivity was demonstrated in 8 of the 54 children and correlated with use of medication for asthma in the 2 years before pulmonary testing and positive parental response to the question, "Does your child wheeze apart from colds?" Airway hyperreactivity did not correlate with a history of other respiratory symptoms or with a history of physician-diagnosed wheezing or asthma. No questionnaire or chart review item identified over 50% of the children with reactive airways, and most subjects identified by each of the items did not demonstrate hyperreactive airways. These data suggest that airway reactivity is only weakly associated with a history of the clinical manifestations of asthma in childhood, in part because children with clinically inactive asthma do not consistently demonstrate airway hyperreactivity and in part because many children with hyperreactive airways have never had respiratory symptoms.

Asthma↗

Breast feeding and maternal smoking as predictors of wheezing in children age 6 to 10 years.

The possibility that controllable environmental factors such as passive smoking and non-breast feeding contribute substantially to wheezing has implications for prevention. Effects of passive smoking and non-breast feeding on wheezing in children aged 6 to 10 years were explored in a historical cohort study of 223 children. Family history of respiratory allergy or asthma, male sex, maternal smoking, and non-breast feeding were significantly associated (p less than 0.05) with wheezing in bivariate analysis. In multivariate loglinear analyses, predictors of wheezing included non-breast feeding (p = 0.05, odds ration = 2.1), male sex (p less than 0.03, odds ratio = 3.1), and family history of respiratory allergy (p less than 0.03, odds ratio = 2.6). In a second model, predictors included an interaction of maternal smoking and family history (p less than 0.005, odds ratio = 4.6) in addition to male sex and family history of respiratory allergy. In further exploration based on tabular analysis, maternal smoking appeared to increase wheezing among children in whom the family history of respiratory allergy was positive (p less than 0.001). Among children in whom the family history of respiratory allergy was negative, non-breast feeding appeared to increase wheezing (p = 0.01). Promotion of breast feeding and reduction of maternal smoking might reduce childhood wheezing.

Breast Feeding↗

Developing prediction rules and evaluating observation patterns using categorical clinical markers: two complementary procedures.

Substantial uncertainty often remains at the time that important diagnostic or therapeutic decisions must be made, despite the availability of multiple clinical indicators. Multiple indicators may be used to define observation patterns that are associated with the presence or absence of disease. Clinical prediction rules based on groups of observation patterns have been used to quantify probabilities and reduce error rates for some medical problems, but efficient use of multiple indicators remains a major challenge in medical practice. Medical outcomes and clinical observations are frequently categorical. Two statistical techniques appropriate for generating prediction rules from categorical data are logit analysis (LA) and recursive partitioning analysis (RPA). LA and RPA were compared in evaluating observation patterns for fractures among 666 upper-extremity injuries in children, and in developing prediction rules for selective radiographic assessment. Fracture estimates and error reductions provided by RPA and LA were very similar. Each technique generated a set of prediction rules with a range of misclassification probabilities, and evaluated the probabilities of fracture for all observation patterns. LA used more information than RPA in observation pattern evaluations, however, and provided fracture estimates specific to each pattern. With currently available statistical software, RPA output provides better statistical guidance in generating prediction rules, whereas LA provides more statistical information of use in evaluating observation patterns. LA warrants attention similar to that conferred on RPA. It appears that complementary use of LA and RPA would be valuable in developing clinical guidelines.

Arm Injuries↗