Biomedical subjects
J B Carlin
Publications and source records attributed to J B Carlin.
Early airway infection, inflammation, and lung function in cystic fibrosis.
AIMS: To determine the relation between lower airway infection and inflammation, respiratory symptoms, and lung function in infants and young children with cystic fibrosis (CF). METHODS: A prospective study of children with CF aged younger than 3 years, diagnosed by a newborn screening programme. All were clinically stable and had testing as outpatients. Subjects underwent bronchial lavage (BL) and lung function testing by the raised volume rapid thoracoabdominal compression technique under general anaesthesia. BL fluid was cultured and analysed for neutrophil count, interleukin 8, and neutrophil elastase. Lung function was assessed by forced expiratory volume in 0.5, 0.75, and 1 second. RESULTS: Thirty six children with CF were tested on 54 occasions. Lower airway infection shown by BL was associated with a 10% reduction in FEV(0.5) compared with subjects without infection. No relation was identified between airway inflammation and lung function. Daily moist cough within the week before testing was reported on 20/54 occasions, but in only seven (35%) was infection detected. Independent of either infection status or airway inflammation, those with daily cough had lower lung function than those without respiratory symptoms at the time of BL (mean adjusted FEV(0.5) 195 ml and 236 ml respectively). CONCLUSIONS: In young children with CF, both respiratory symptoms and airway infection have independent, additive effects on lung function, unrelated to airway inflammation. Further studies are needed to understand the mechanisms of airway obstruction in these young patients.
Is isopropyl alcohol swabbing before injection really necessary?
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Does bullying cause emotional problems? A prospective study of young teenagers.
OBJECTIVES: To establish the relation between recurrent peer victimisation and onset of self reported symptoms of anxiety or depression in the early teen years. DESIGN: Cohort study over two years. SETTING: Secondary schools in Victoria, Australia. PARTICIPANTS: 2680 students surveyed twice in year 8 (aged 13 years) and once in year 9. MAIN OUTCOME MEASURES: Self reported symptoms of anxiety or depression were assessed by using the computerised version of the revised clinical interview schedule. Incident cases were students scoring >/=12 in year 9 but not previously. Prior victimisation was defined as having been bullied at either or both survey times in year 8. RESULTS: Prevalence of victimisation at the second survey point in year 8 was 51% (95% confidence interval 49% to 54%), and prevalence of self reported symptoms of anxiety or depression was 18% (16% to 20%). The incidence of self reported symptoms of anxiety or depression in year 9 (7%) was significantly associated with victimisation reported either once (odds ratio 1.94, 1.1 to 3.3) or twice (2.30, 1.2 to 4.3) in year 8. After adjustment for availability of social relations and for sociodemographic factors, recurrent victimisation remained predictive of self reported symptoms of anxiety or depression for girls (2.60, 1.2 to 5.5) but not for boys (1.36, 0.6 to 3.0). Newly reported victimisation in year 9 was not significantly associated with prior self report of symptoms of anxiety or depression (1.48, 0.4 to 6.0). CONCLUSION: A history of victimisation and poor social relationships predicts the onset of emotional problems in adolescents. Previous recurrent emotional problems are not significantly related to future victimisation. These findings have implications for how seriously the occurrence of victimisation is treated and for the focus of interventions aimed at addressing mental health issues in adolescents.
Parental 'affectionless control' in adolescent depressive disorder.
BACKGROUND: Adults with depressive disorder report high rates of sub-optimal maternal care in childhood. Despite the greater salience of relationships with parents earlier in life, associations with parenting style have not yet been systematically studied in adolescent onset disorder. METHODS: A six-wave, 3-year study of adolescent health in 2032 Australian secondary school students provided an opportunity to undertake a two-phase study of early onset depression. Between waves 2 to 6, a self-administered computerised form of the revised Clinical Interview Schedule (CIS-R) was used to generate a first phase diagnosis of ICD-10 depressive episode. Each subject with a CIS-R-defined depressive episode was selected for second phase assessment together with two subjects from the CIS-R non-cases in each school. Second phase assessment included a second diagnostic assessment using the depression and hypomania modules of the Composite International Diagnostic Interview (CIDI) and assessment of paternal and maternal style using the Parental Bonding Instrument. RESULTS: A total of 1947 out of 2032 subjects in the sampling frame (95.8%) participated in the cohort study (phase 1) at least once; 406 (94%) of the 435 selected subjects completed second phase assessment. One hundred and nineteen subjects fulfilled criteria for depressive episode on the CIS-R at one or more waves. Over the 30-month study period, 69 subjects (10 male, 59 female) fulfilled both CIS-R and CIDI definitions of depression at the same wave and were classified as 'definite depressive disorder'. Low maternal and paternal care held independent associations with both definitions of depression, with the effects clearest in those in the lowest quartile of reported care. After adjusting for low parental care, the associations between high parental control and depression were small. CONCLUSIONS: Sub-optimal parenting is associated with depressive disorder in adolescents. Low maternal and paternal care are each associated with a two- to three-fold higher rate of depressive disorder. These findings are consistent with an effect of sub-optimal parenting on the onset rather than course of disorder. Whether sub-optimal parenting is associated with a risk for the onset of depression outside the adolescent years has yet to be clarified.
Reliability of the Melbourne assessment of unilateral upper limb function.
This study examines the reliability of the Melbourne Assessment of Unilateral Upper Limb Function: a quantitative test of quality of movement in children with neurological impairment. The assessment was administered to 20 children aged from 5 to 16 years (mean age 9 years 10 months, SD 2 years 10 months) who had various types and degrees of cerebral palsy (CP). The performances of the 20 children during assessment were videotaped for subsequent scoring by 15 occupational therapists. Scores were analyzed for internal consistency of test items, inter- and intrarater reliability of scorings of the same videotapes, and test-retest reliability using repeat videotaping. Results revealed very high internal consistency of test items (alpha=0.96), moderate to high agreement both within and between raters for all test items (intraclass correlations of at least 0.7) apart from item 16 (hand to mouth and down), and high interrater reliability (0.95) and intrarater reliability (0.97) for total test scores. Test-retest results revealed moderate to high intrarater reliability for item totals (mean of 0.83 and 0.79) for each rater and high reliability for test totals (0.98 and 0.97). These findings indicate that the Melbourne Assessment of Unilateral Upper Limb Function is a reliable tool for measuring the quality of unilateral upper-limb movement in children with CP.
Statistics for clinicians: 4: Basic concepts of statistical reasoning: hypothesis tests and the t-test.
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5: comparing proportions using the chi-squared test.
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Comparison of means and proportions using confidence intervals.
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Clinical outcome after early Pseudomonas aeruginosa infection in cystic fibrosis.
OBJECTIVE: To determine the clinical consequences of acquiring Pseudomonas aeruginosa infection during early childhood in children with cystic fibrosis (CF). DESIGN: Prospective, observational cohort study of 56 children with CF identified by newborn screening during 1990-92. Each child underwent an annual bronchial lavage during the first 2 to 3 years of life. Clinical outcome was determined at 7 years of age. RESULTS: P aeruginosa infection was diagnosed in 24 (43%) cohort subjects. Four children died before 7 years of age, all of whom had been infected with a multi-resistant, mucoid strain of P aeruginosa (P =.04). In survivors, P aeruginosa infection was associated with significantly increased morbidity as measured by lower National Institutes of Health scores, greater variability in lung function, increased time in the hospital, and higher rates of recombinant human deoxyribonuclease therapy (P <.01). In this young CF cohort, best forced expiratory volume in 1 second was an insensitive measure of increased morbidity. CONCLUSIONS: Acquisition of P aeruginosa was common by 7 years of age in this CF birth cohort and was associated with increased morbidity and mortality. An improved disease severity score would improve the evaluation and study of early CF lung disease.
Epidemiological patterns of rotaviruses causing severe gastroenteritis in young children throughout Australia from 1993 to 1996.
Rotavirus strains that caused severe diarrhea in 4,634 (2,533 male) children aged less than 5 years and admitted to major hospitals in eight centers throughout Australia from 1993 to 1996 were subject to antigenic and genetic analyses. The G serotypes of rotaviruses were identified in 81.9% (3,793 of 4,634) children. They included 67.8% (from 3,143 children) serotype G1 isolates (containing 46 electropherotypes), 11.5% (from 531 children) serotype G2 isolates (27 electropherotypes), 0.8% (from 39 children) serotype G3 isolates (8 electropherotypes), and 1.6% (from 76 children) serotype G4 isolates (9 electropherotypes). G6 (two strains) and G8 (two strains) isolates were identified during the same period. G1 serotypes were predominant in all centers, with intermittent epidemics of G2 serotypes and sporadic detection of G3 and G4 strains. With the exception of two strains (typed as G1P2A[6] and G2P2A[6]) all serotype G1, G3, and G4 strains were P1A[8] and all serotype G2 strains were P1B[4]. Two contrasting epidemiological patterns were identified. In all temperate climates rotavirus incidence peaked during the colder months. The genetic complexity of strains (as judged by electropherotype) was greatest in centers with large populations. Identical electropherotypes appeared each winter in more than one center, apparently indicating the spread of some strains both from west to east and from east to west. Centers caring for children in small aboriginal communities showed unpredictable rotavirus peaks unrelated to climate, with widespread dissemination of a few rotavirus strains over distances of more than 1,000 km. Data from continued comprehensive etiological studies of genetic and antigenic variations in rotaviruses that cause severe disease in young children will serve as baseline data for the study of the effect of vaccination on the incidence of severe rotavirus disease and on the emergence of new strains.
Interlobar differences in bronchoalveolar lavage fluid from children with cystic fibrosis.
Bronchoalveolar lavage (BAL) performed in specialist centres has improved the understanding of infant cystic fibrosis (CF) lung disease. As most researchers sample from a single lobe, it was determined whether BAL results could be generalized to other lung segments. Thirty-three CF children, aged 1.5-57 months, underwent in random order sequential BAL of their right middle and lingula lobes. Specimens from each lobe had separate quantitative bacteriology, cytology and cytokine analysis. Bacterial counts > or = 1 x 10(5) colony forming units (cfu) x mL(-1) were observed in nine (27%) subjects, including six involving only the right middle lobe. These six children had similar inflammatory indices in their right middle and lingula lobes, and interleukin (IL)-8 concentrations in the latter were significantly higher than that observed within the lingula lobes of the 24 CF children with bacterial counts < 1 x 10(5) cfu x mL(-1). Lingula neutrophil and IL-8 levels correlated best with right middle lobe bacteria numbers. This observational study in cystic fibrosis children suggests that while inflammation is detected in both lungs, bacterial distribution may be more inhomogeneous. Bronchoalveolar lavage microbiological findings from a single lobe may therefore, not be generalized to other lung segments. When performing bronchoalveolar lavage in cystic fibrosis children, it is important to sample from multiple sites.
Tutorial in biostatistics. Meta-analysis: formulating, evaluating, combining, and reporting by S-L. T. Normand, Statistics in Medicine, 18, 321-359 (1999)
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Anticonvulsant teratogenesis 4: inter-rater agreement in assessing minor physical features related to anticonvulsant therapy.
BACKGROUND: We report on inter-rater agreement in the assessment of newborn infants with respect to a range of minor physical features in a cohort study of the fetal effects of maternal anticonvulsant use during pregnancy. METHODS: Infants from three groups (exposed to anticonvulsants, seizure history but no medication exposure, and unexposed controls) were examined by both a pediatrician/teratologist, who was blinded with respect to the mother's exposure status, and an unblinded research assistant. Agreement on assessments for selected anomalies associated with anticonvulsant therapy was measured by kappa-statistics, as well as by more sensitive log-linear modeling techniques, which allow examination of possible covariate effects on the strength of agreement. Although the physician and research assistant agreed on a high proportion of cases (80-90%), kappa values were modest (0.2-0. 5), partly because of the low prevalence of the anomalies considered. To explore how agreement varies within subgroups, we used recently developed methods for studying agreement based on log-linear models. RESULTS: Log-linear modeling indicated that there was substantial variation in pattern of agreement between different individual research assistants but that other factors (e.g., exposure category, sex, and birthweight) did not appear to be related to agreement. Our results suggest that research assistants with more experience showed the highest degree of agreement with the physicians. CONCLUSIONS: Our results have implications for both clinical practice and epidemiologic research and underline the importance of thorough training of staff in the definitions to be used and also the need for multiple independent assessments of these subtle anomalies.
Statistics for clinicians. 1: Introduction.
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2: describing and displaying data.
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3: Basic concepts of statistical reasoning: standard errors and confidence intervals.
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Adolescent depressive disorder: a population-based study of ICD-10 symptoms.
OBJECTIVE: Earlier studies have suggested that symptoms of depressive disorder in adolescents may differ from those found in adults. Even so, diagnostic criteria developed in adults have come to be widely applied to younger subjects. This study examines the frequency of ICD-10 symptoms in depressive disorder and their association with severity in a large community sample of adolescents aged 15 to 18 years. METHOD: A six-wave prospective study of adolescent health and emotional wellbeing in 2032 Australian secondary school students provided an opportunity to conduct a two-phase study of adolescent onset depression. A self-administered computerised form of the revised Clinical Interview Schedule (CIS-R) was used as a first phase diagnostic measure. Second phase assessment using the Composite International Diagnostic Interview (CIDI) allowed the delineation of a group fulfilling criteria on both instruments. The ICD-10 symptoms and severity profiles for depression were generated with standard algorithms. RESULTS: 1947 (95.8%) out of 2032 subjects in the designated sample completed phase 1 assessment at least once. Participation rates at phase 2 interviews were 93%. Over the 30-month study period 69 subjects (10 male, 59 female) fulfilled criteria for ICD-10 depressive episodes on both the CIS-R and CIDI. Thirty-one per cent (n = 21) had experienced a severe episode, 46% (n = 32) moderate and 23% (n = 16) mild episodes. Loss of interest and pleasure, decreased energy and fatigue, sleep disturbance, suicidal ideation and diminished concentration most clearly distinguished adolescents with depressive disorder from controls. Self-reproach and guilt, psychomotor agitation and/or retardation and appetite disturbance with weight change showed the clearest increase in frequency with increasing severity of episode. The somatic syndrome was reported by close to one in three of those with a severe depressive episode, but was uncommon in those with mild and moderate episodes. CONCLUSIONS: The ICD-10 diagnostic criteria are applicable to depressive disorder in older adolescents. With the exception of depressed mood, found in one in five non-cases, all other symptoms were common in cases and uncommon in non-cases. Practitioner awareness of symptoms indicating the presence and severity of disorder should enhance early identification and choice of treatment in adolescent depression.