The Canadian Childhood Asthma Primary Prevention Study: outcomes at 7 years of age. The PREVASC study: the clinical effect of a multifaceted educational intervention to prevent childhood asthma. The Canadian asthma primary prevention study: outcomes at 2 years of age. Effects of a dietary and environmental prevention programme on the incidence of allergic symptoms in high atopic risk infants: three years' follow-up. Three-year outcomes of dietary fatty acid modification and house dust mite reduction in the Childhood Asthma Prevention Study. Asthma education by community child health nurses. An education intervention for childhood asthma by Aboriginal and Torres Strait Islander health workers: a randomised controlled trial. Prevention of asthma during the first 5 years of life: a randomized controlled trial. Three-year follow-up of clinical and inflammation parameters in children monosensitized to mites undergoing sub-lingual immunotherapy.
Avoidance of any one of the individual risk factors associated with childhood asthma has not been successful in preventing its development.
                The purpose of this study is to determine the effectiveness of a multifaceted intervention program for the primary prevention of asthma in high-risk infants at 7 years of age.
                Five hundred forty-five high-risk infants with an immediate family history of asthma and allergies were prospectively randomized into intervention or control groups prenatally. Intervention measures introduced before birth and during the first year of life included avoidance of house dust, pets, and environmental tobacco smoke and encouragement of breast-feeding with delayed introduction of solid foods. Assessment of outcomes at 7 years consisted of examination by pediatric allergists, methacholine inhalation tests, and allergy skin tests.
                At 7 years, 469 of the 545 children were contacted, and 380 returned for further assessment. The prevalence of pediatric allergist-diagnosed asthma was significantly lower in the intervention group than in the control group (14.9% vs 23.0%; adjusted risk ratio, 0.44; 95% CI, 0.25-0.79). The prevalence of allergic rhinitis, atopic dermatitis, atopy (defined as positive skin test reactions to any common allergen), and bronchial hyperresponsiveness (defined as the provocative concentration of methacholine that induced a 20% decrease in FEV 1 from a postsaline value of less than 7.8 mg/mL) were not significantly different between the 2 groups. The prevalence of asthma (defined as wheeze without colds and the presence of bronchial hyperresponsiveness) was also significantly lower in the intervention group compared with the control group (12.9% vs 25.0%; adjusted risk ratio, 0.39; 95% CI, 0.22-0.71).
                The multifaceted intervention program was effective in reducing the prevalence of asthma in high-risk children at 7 years of age. As asthma is the most common chronic disease in childhood, much attention is directed towards primary prevention. Here, the clinical effectiveness of a multifaceted educational prevention was studied. A total of 476 high-risk children were recruited during the prenatal period by general practitioners and randomised to either: 1) a control group, receiving usual care; or 2) an intervention group in which families received instruction from nurses on how to reduce exposure of newborns to mite, pet and food allergens, and passive smoking. A total of 443 infants were followed-up for 2 yrs. At 2 yrs of age, the intervention group (n = 222) had less asthma-like symptoms, including wheezing, shortness of breath and night-time cough, than the control group (n = 221). No significant differences in total and specific immunoglobulin E were found between the groups. During the first 2 yrs of life, the incidence of asthma-like symptoms was similar in both groups; however, subanalysis revealed a significant reduction in the female, but not in the male, intervention group. In conclusion, the intervention used in this study was not effective in reducing asthma-like symptoms in high-risk children during the first 2 yrs of life, although it was modestly effective at 2 yrs. Follow-up is necessary to confirm whether the intervention can actually prevent the development of asthma. Avoidance of individual risk factors have not been successful in preventing the development of asthma.
                We sought to determine the effectiveness of a multifaceted intervention program in primary prevention of asthma in high-risk infants.
                We identified 545 high-risk infants on the basis of an immediate family history of asthma. Families were randomized into intervention or control groups. Intervention measures included avoidance of house dust mite, pet allergen, and environmental tobacco smoke. Breast-feeding was encouraged with formula supplementation if necessary, and introduction of solid foods was delayed.
                At 2 years of age, 19.5% of the children had asthma, and 14.7% had atopy (positive skin test response to one or more common allergens). Significantly fewer children had asthma in the intervention group compared with in the control group (16.3% vs 23.0%), with 60% less persistent asthma at 2 years. There was a 90% reduction for recurrent wheeze in the intervention group compared with that seen in the control group. Exposure to maternal environmental tobacco smoke during pregnancy or the first year was a risk factor for asthma at 2 years of age. A positive skin test response, particularly to food, at 12 months predicted asthma at 2 years. There was no significant difference for atopy between the intervention and control groups, but daycare reduced atopy at 2 years.
                This multifaceted intervention program during a window of opportunity in the first year of life was effective in preventing asthma in high-risk children at 2 years of age. Future studies with this cohort at school age are important. A prospective case-control study is presented to assess an allergy prevention programme in children up to 36 months of age. Infants born at three maternity hospitals were followed from birth: 279 infants with high atopic risk (intervention group) were compared with 80 infants with similar atopic risk but no intervention (non-intervention group). The intervention programme included dietary measures (exclusive and prolonged milk feeding diet followed by a hypoantigenic weaning diet) and environmental measures (avoidance of parental smoking in the presence of the babies, day care > 2 years of life). Mothers in this group who had insufficient breast milk were randomly assigned to one of two coded formulas: either a hydrolysed milk formula (Nidina HA, Nestlé) or a conventional adapted formula (Nan, Nestlé). Other environmental measures remained the same as for the breastfeeding mothers. The non-intervention group were either breastfed or received the usual Italian milk feeding and weaning diet, without environmental advice. The main outcome measures were anthropometric measurements and allergic disease manifestations. Normal anthropometric data were observed both in the intervention group and in the non-intervention group. The incidence of allergic manifestations was much lower in the intervention group than in the non-intervention group at 1 year (11.5 versus 54.4%, respectively) and at 2 years (14.9 versus 65.6%) and 3 years (20.6 versus 74.1%). Atopic dermatitis and recurrent wheezing were found in both the intervention group and the non-intervention group from birth up to the second year of life, while urticaria and gastrointestinal disorders were only present in the non-intervention group in the first year of life. Conjunctivitis and rhinitis were present after the second year in both the intervention group and the non-intervention group. Relapse of the same allergic symptom was less in the intervention group (13.0%) than in the non-intervention group (36.9%). In comparison to the non-intervention group, there were fewer intervention group cases with two or more different allergic symptoms (8.7 versus 32.6%), and they were more likely to avoid steroid treatment (0 versus 10.8%) and hospital admission (0 versus 6.5%). Babies in the non-intervention group fed with adapted formula were more likely to develop allergies than breastfed babies in the same group. In the intervention group the breastfed infants had the lowest incidence of allergic symptoms, followed by the infants fed the hydrolysed formula (ns). Infants in the intervention group fed the adapted formula had significantly more allergies than the breastfed and hydrolysed milk fed infants, although less than their counterparts in the non-intervention group. Of the affected subjects in the intervention group, 80.4% were RAST and/or Prick positive to food or inhalant allergens. Total serum IgE values detected at birth in the intervention group were not predictive, but at 1 and 2 years of age, IgE values more than 2 SD above the mean in asymptomatic babies were found to predictive for later allergy. In breastfed babies the total IgE level at 1 and 2 years of age was lower than in the other two feeding groups. Of the various factors tested in the non-intervention group, the following were the most important in the pathogenesis of allergic symptoms: (i) formula implementation begun in the first week of life; (ii) early weaning (< 4 months); (iii) feeding beef (< 6 months); (iv) early introduction of cow's milk (< 6 months); and (v) parental smoking in the presence of the babies and early day care admission (< 2 years of life). All the preventive measures used in this study (exclusive breastfeeding and/or hydrolysed milk feeding, delayed and selective introduction of solid foods, and environmental advice) were effective at the third year of follow-up, greatly reducing allergic manifestations in high atopic risk babies in comparison with those not receiving these interventions Two factors thought to influence the risk of asthma are the promoting effect of sensitization to house dust mites and the preventive effect of increased omega-3 fatty acids. Although house dust mite allergen avoidance has been used as a preventive strategy in several trials, the effect of omega-3 fatty acid supplementation in the primary prevention of asthma and allergic disease is not known.
                To measure the effects of dietary supplementation with omega-3 fatty acids and house dust mite allergen avoidance in children with a family history of asthma.
                A total of 616 children at high risk of asthma were enrolled antenatally in a randomized controlled trial, and 526 children remained in the trial at age 3 years. The outcomes were symptoms of allergic disease and allergen sensitization.
                There was a significant 10.0% (95% CI, 3.7-16.4) reduction in the prevalence of cough in atopic children in the active diet group ( P=.003; number needed to treat, 10) but a negligible 1.1% (95% CI, -7.1 to 9.5) reduction cough among nonatopic children. There was a 7.2% (95% CI, 10.11-14.3) reduction in sensitization to house dust mite in the active allergen avoidance group ( P=.05; number needed to treat, 14). No significant differences in wheeze were found with either intervention.
                These results suggest that our interventions, designed to be used in simple public health campaigns, may have a role in preventing the development of allergic sensitization and airways disease in early childhood. This offers the prospect of reducing allergic disease in later life. A randomised controlled study of an educational programme for children with asthma and their families was carried out by community child health nurses. Three hundred and sixty eight children aged 2 to 14 years were enrolled in the study after admission to hospital for asthma. The intervention group was visited monthly by a nurse for six months. The subjects were assessed six months later by a postal, self administered questionnaire. European children in the intervention group were taking significantly more drugs for the treatment of asthma six months after the index admission to hospital than those in the control group (mean (SD) intake 2.7 (1.1) v 2.1 (1.0), respectively). In particular, they were using more theophylline (56.6% v 37.0%) and inhaled steroids (34.9% v 21.0%). There was no difference between the groups for parental reports of improvement, of missed schooling, and in severe attacks of asthma of not responding to the usual treatment at home. European children in the intervention group used the hospital services for severe attacks of asthma more than controls (34.2% v 10.5%). There were more re-admissions in the European intervention group in the subsequent six months after the index admission than in the control group (mean (SD) 0.51 (0.97) v 0.29 (0.65). Re-admission continued to be higher in the 12 months after the nurse had stopped visiting (0.81 (1.65) v 0.25 (0.65]. There was no difference in the duration of hospital stay between the intervention and control groups. For Polynesian children there was no difference between the groups for any outcome measures. To assess the outcomes of an education intervention for childhood asthma conducted by Australian Indigenous health care workers (IHCWs).
                Randomised controlled trial in a primary health care setting on Thursday Island and Horn Island, and in Bamaga, Torres Strait region of northern Australia, April 2005 to March 2007.
                88 children, aged 1-17 years, with asthma diagnosed by a respiratory physician (intervention group, 35; control group, 53; 98% Indigenous children).
                Children were randomly allocated to: (i) three additional asthma education sessions with a trained IHCW, or (ii) no additional asthma education. Both groups were re-assessed at 12 months.
                Primary endpoint: number of unscheduled visits to hospital or a doctor caused by asthma exacerbation. Secondary outcomes: measures of quality of life (QoL) and functional severity index; asthma knowledge and understanding of asthma action plans (AAPs); and school days missed because of wheezing.
                The groups were comparable at baseline (except for asthma severity, which was adjusted for in the analysis). There were no significant differences in the primary outcome (number of unscheduled medical visits for asthma). School children in the intervention group missed fewer school days because of wheezing (100% < 7 days v 21% of those in the control group missed 7-14 days). Significantly more carers in the intervention group could answer questions about asthma medication, knew where their AAP was kept (84% v 56%), and were able to describe the plan (67% v 40%). In both the intervention and control groups (before-and-after comparison), there was a significantly reduced frequency of asthma exacerbations, as well as an improved QoL score and functional severity index, with no significant differences between the groups.
                A community-based asthma education program conducted by trained IHCWs improves some important asthma outcomes in Indigenous children with asthma.
                Australian Clinical Trials Registry ACTRN012605000718640. Early life exposures may be important in the development of asthma and allergic disease.
                To test house dust mite (HDM) avoidance and dietary fatty acid modification, implemented throughout the first 5 years of life, as interventions to prevent asthma and allergic disease.
                We recruited newborns with a family history of asthma antenatally and randomized them, separately, to HDM avoidance or control and to dietary modification or control. At age 5 years, they were assessed for asthma and eczema and had skin prick tests for atopy.
                Of 616 children randomized, 516 (84%) were evaluated at age 5 years. The HDM avoidance intervention resulted in a 61% reduction in HDM allergen concentrations (microg/g dust) in the child's bed but no difference in the prevalence of asthma, wheeze, or atopy (P > .1). The prevalence of eczema was higher in the active HDM avoidance group (26% vs 19%; P = .06). The ratio of omega-6 to omega-3 fatty acids in plasma was lower in the active diet group (5.8 vs 7.4; P < .0001). However, the prevalence of asthma, wheezing, eczema, or atopy did not differ between the diet groups (P > .1).
                Further research is required to establish whether other interventions can be recommended for the prevention of asthma and allergic disease.
                House dust mite avoidance measures and dietary fatty acid modification, as implemented in this trial during infancy and early childhood, did not prevent the onset of asthma, eczema, or atopy in high-risk children. Parallel follow-up of clinical and inflammatory markers during sub-lingual immunotherapy (SLIT) is highly beneficial. Twenty-four children (age 4-16) monosensitized to house dust mite were randomized to receive either active or placebo SLIT for 1 yr in a double-blind placebo controlled design (Marcucci et al., Allergy 2003: 58: 657-62). Thereafter, for 2 yr they all received active treatment. Symptom scores for rhinitis, asthma, and drug usage were daily recorded. Eosinophil cationic protein (ECP) and tryptase in sputum and nasal secretions, serum and nasal mite-specific immunoglobulin E (IgE) were recorded before treatment and at 10-12 months intervals. Nasal ECP and nasal tryptase after specific nasal provocation tests were significantly reduced as compared to baseline values (p = 0.0043 and 0.0195, respectively) in the third year of active treatment. None of the other inflammatory parameters was increased. In placebo treated patients all these parameters tended to decrease only after switching to active treatment. Clinical scores did not improve in treated vs. placebo patients in the double-blind placebo-controlled phase of the study. In both cohorts a clinical benefit was observed as intra-group score reduction as compared to baseline. A significant difference was reached in patients treated for 2 yr for rhinitis and asthma (p = 0.0009 and 0.0019, respectively) but not for drug usage and in patients treated for 3 yr for rhinitis, asthma, and drug usage (p = 0.0105, 0.0048, and 0.02, respectively). SLIT in children monosensitized to mites reverted the spontaneous increase in nasal IgE and in local parameters of allergic inflammation. These outcomes were followed by a consolidated clinical improvement in the second and third year of treatment.
The available evidence suggests that the reduction of exposure to multiple allergens compared to usual care reduces the likelihood of a current diagnosis of asthma in children (at ages < 5 years and 5 years and older). Mono-intervention studies have not produced effects which are statistically significant compared with control. In children who are at risk of developing childhood asthma, multifaceted interventions, characterised by dietary allergen reduction and environmental remediation, reduce the odds of a physician diagnosis of asthma later in childhood by half. This translates to a number needed to treat (NNT) of 17. The effect of multi-faceted interventions on parent reported wheeze was inconsistent and had no significant impact on nocturnal coughing or dyspnoea. Data from monofaceted intervention exposed children studies were not significantly different from those of control groups for all outcomes. There remains uncertainty as to whether multiple interventions are more effective than mono-component interventions. The comparisons made were indirect, making the conclusions drawn uncertain. To our knowledge there are no ongoing studies in which both intervention strategies are randomly compared. The findings, however, warrant further direct comparison between multiple- and monofaceted interventions aimed at reducing the prevalence of asthma in children.