Components of primary care interventions to treat childhood overweight and obesity: a systematic review of effect.

The primary care setting presents an opportunity for intervention of overweight and obese children but is in need of a feasible model-of-care with demonstrated effectiveness. The aims were to (i) identify controlled interventions that treated childhood overweight or obesity in either a primary care setting or with the involvement of a primary healthcare professional and (ii) examine components of those interventions associated with effective outcomes in order to inform future intervention trials in primary care settings. Major health and medicine databases were searched: MEDLINE, CINAHL, EMBASE, Cochrane Reviews, CENTRAL, DARE, PsychINFO and ERIC. Articles were excluded if they described primary prevention interventions, involved surgical or pharmacological treatment, were published before 1990 or not published in English. Twenty-two papers describing 17 studies were included. Twelve studies reported at least one significant intervention effect. Comparison of these 12 interventions provides evidence for: training for health professionals before intervention delivery; behaviour change options (including healthy diet, activity and sedentary behaviour); effecting behaviour change via a combination of counselling, education, written resources, support and motivation; and tailoring intensity according to whether behavioural, anthropometric or metabolic changes are the priority. These components are practicable to future intervention studies in primary care.

General practice vs surgical-based follow-up for patients with colon cancer: randomised controlled trial.

This trial examined the optimal setting for follow-up of patients after treatment for colon cancer by either general practitioners or surgeons. In all, 203 consenting patients who had undergone potentially curative treatment for colon cancer were randomised to follow-up by general practitioners or surgeons. Follow-up guidance recommended three monthly clinical review and annual faecal occult blood tests (FOBT) and were identical in both study arms. Primary outcome measures (measured at baseline, 12 and 24 months were (1) quality of life, SF-12; physical and mental component scores, (2) anxiety and depression: Hospital Anxiety and Depression Scale and (3) patient satisfaction: Patient Visit-Specific Questionnaire. Secondary outcomes (at 24 months) were: investigations, number and timing of recurrences and deaths. In all, 170 patients were available for follow-up at 12 months and 157 at 24 months. At 12 and 24 months there were no differences in scores for quality of life (physical component score, P=0.88 at 12 months; P=0.28 at 24 months: mental component score, P=0.51, P=0.47; adjusted), anxiety (P=0.72; P=0.11) depression (P=0.28; P=0.80) or patient satisfaction (P=0.06, 24 months). General practitioners ordered more FOBTs than surgeons (rate ratio 2.4, 95% CI 1.4-4.4), whereas more colonoscopies (rate ratio 0.7, 95% CI 0.5-1.0), and ultrasounds (rate ratio 0.5, 95% CI 0.3-1.0) were undertaken in the surgeon-led group. Results suggest similar recurrence, time to detection and death rates in each group. Colon cancer patients with follow-up led by surgeons or general practitioners experience similar outcomes, although patterns of investigation vary.

Osteoporosis screening in people with airways disease.

We tested associations between risk factors and bone mineral density in airways disease subjects, and developed a clinical screening tool to identify people who could benefit from bone mineral density testing. Subjects were recruited through hospital outpatients and pharmacies (Newcastle, n = 172). With survey refinement, we then tested a revised tool in a second sample (Adelaide, n = 317). Study factors included oral/inhaled corticosteroid use, asthma severity, respiratory admissions, physical activity, percent predicted forced expiratory volume in one second (FEV1), body mass index, and smoking history. Outcomes were bone mineral density of lumbar vertebra (L2-4) and total (or neck of) femur. Analysis was logistic regression with generation of a simple screening algorithm based upon coefficients. Scoring algorithm risk factors for T-score of < - 2.0: age > or = 68 = 10 points, bone mineral density < 20 = 25, weight < 60 kg = 20, 60-69 kg = 10, > or = 80 cigarette pack years = 15, low-level leisure activity = 5, area under receiver operator curve 0.83. For a cut-off score of 10, sensitivity was 91.2%, specificity 53.9%, positive and negative predictive values 52.3 and 91.7%, and 67.2% were correctly classified. In conclusions, our model has acceptable sensitivity, although limited specificity. Use of this tool may reduce unnecessary referrals for bone mineral density measurement.

Randomised trials within the general practice evaluation program. Why so few?

BACKGROUND: The General Practice Evaluation Program (GPEP) provided competitive funding for general practice research from 1990-1999. METHODS: Projects funded by GPEP between November 1990 and December 1999 were audited to determine the extent of randomised trials and other interventional studies. RESULTS: Thirty-three (13%) of the 248 projects were interventional studies; of these 21 (8% of all projects) were randomised trials. CONCLUSIONS: While GPEP has made a significant contribution toward Australian general practice research, few randomised trials and other interventional studies have been funded. Reasons include the specific evaluative focus and restrictions on project duration and funding. Randomised trials should be supported within future general practice research funding.

Health effects of daily indoor nitrogen dioxide exposure in people with asthma.

Household gas appliances produce nitrogen dioxide (NO2), which may be associated with an increase in symptoms in asthmatics. The relationship between indoor NO2 exposure, and respiratory symptoms in people with asthma was evaluated. Self-reported asthmatics (n=125) wore lapel badges that measured NO2 daily over 6 weeks at home. Outdoor pollutants, spores and meteorological parameters were measured daily, in addition to smoking status and demographic factors. Seven asthma symptoms were recorded in diaries, for analysis by same day and also with 1 day lag exposures, using a generalized estimating equation. Significant interactions were demonstrated between NO2 at age < or =14 yrs, with respect to the symptoms of chest tightness on the same day (odds ratio (OR): 1.29, 95% confidence interval (CI): 1.16-1.43) and with a 1 day lag (OR: 1.29, 95% CI: 1.14-1.46), breathlessness on exertion with a 1 day lag (OR: 1.13, 95% CI: 1.00-1.28), daytime asthma attacks on the same day (OR: 1.13, 95% CI: 1.02-1.26) night asthma attacks on the same day (OR: 1.16, 95% CI:1.03-1.30) and with a 1 day lag (OR: 1.15, 95% CI; 1.03-1.29) after adjustment for potential confounders. A significant interaction between NO2 and age 35-49 yrs was demonstrated for coughs with a 1 day lag (OR: 1.15, 95% CI: 1.01-1.31). Daily personal exposures to NO2 are associated with asthmatic symptoms in children.

Randomised controlled trial of general practice based asthma clinics.

OBJECTIVE: To compare the effects on asthma morbidity of asthma clinics based in general practice with standard general practice care. DESIGN AND SETTING: A randomised controlled trial in eight general practices. Patients, general practitioners and outcomes assessors were not blinded to treatment allocation. PARTICIPANTS: 195 patients with asthma aged 5-64 years; 191 completed the trial. INTERVENTION: Three asthma clinic sessions over six months involving nurse counselling, education about asthma management, spirometry and consultation with the general practitioner. MAIN OUTCOME MEASURES: Patients reporting days lost from work or school, number of days lost, the presence of morning or nocturnal asthma symptoms, use of an action plan, medication use, current smoking, hospitalisation, and emergency visits. RESULTS: Asthma clinics were associated with a greater reduction in nocturnal symptoms, an increase in the ownership of peak flow meters and an increase in the number of patients commencing or resuming smoking. Both control and intervention groups showed similar improvement in days lost from work or school, the presence of symptoms, use of an action plan and taking reliever medication. CONCLUSION: Our study does not show that asthma clinics are more effective than standard general practice care in reducing asthma morbidity. It is uncertain how much of the improvement in outcomes was due to the asthma clinic, the influence of the study itself upon patients and practitioners, or other factors, such as the tendency for a patient's asthma management to improve over time.

Cyanobacterial (blue-green algae) contamination in drinking water and perinatal outcomes.

OBJECTIVE: The aim of this ecological study was to examine the relationship between potential cyanobacterial exposure through drinking water during pregnancy and birth outcomes. METHOD: One hundred and fifty-six communities in South-Eastern Australia were involved, providing 32,700 singleton live newborn during the period 1992-94. Cyanobacterial occurrence and cell density (alert level) in drinking water sources during the first trimester, the total gestational period for premature births or limited to 36 weeks in term infants, and the last 12 weeks prior to preterm births or up to and including 36 weeks in term infants were used as estimates of exposure. RESULTS: There were statistically significant differences between the proportion of time during the first trimester with cyanobacterial occurrence and the percentage of births that were low birth weight (LBW) and very low birth rate (VLBW). Significant differences were also found among various categories of first trimester exposure based on average cell density and LBW, prematurity and congenital defects. However, the pattern of these results does not suggest a causal link to cyanobacteria. There were no clear dose-response relationships. Analyses based on exposure during the last 12 weeks and total gestation also showed no significant dose-response effects. CONCLUSION: The results of this study provide no clear evidence for an association between cyanobacterial contamination of drinking water sources and adverse pregnancy outcomes.

Antibiotic resistance in Streptococcus pneumoniae isolated from children.

OBJECTIVE: To determine the level of antibiotic resistance in pneumoniae (S. pneumoniae) isolated from nasal swabs of healthy children. METHOD: Cross-sectional community survey. SETTING: Survey was undertaken in general practice settings in Canberra during March and April 1998. SUBJECTS: Four hundred and sixty-one children under 3 years of age enrolled in general practice trial of clinical practice guidelines for antibiotic use. OUTCOME MEASURES: Resistance to penicillin, erythromycin, co-trimoxazole, tetracycline, chloramphenicol and cefotaxime among the isolates of S. pneumoniae. RESULTS: A total of 461 nasal swabs were collected and S. pneumoniae was isolated from 171 (37.1%). Penicillin resistance was found in 12.3% of these isolates, with high level resistance in 0.6%. Resistance rates were higher for cotrimoxazole (44.4%) and erythromycin (18.1%) than for penicillin. Multidrug resistance was found in 19% of these isolates. There was a significant association between the attendance at a day care centre and carriage of pneumococcus (53% vs 32%, odds ratio (OR) 2.4, 95% confidence interval (CI) 1.5-3.7, P < 0.001). Children who attended day care centers and had received antibiotics during the 4 months prior to swab collection were three times more likely to carry an antibiotic-resistant isolate than children who had neither attended a day care centre nor received antibiotics (68% vs 40%, OR 3.1, 95% CI 1.2-8.4, P = 0.02). CONCLUSION: The level of antibiotic resistance in pneumococci from healthy children was of concern. Carriage of pneumococcus was significantly higher in children who attended a day care centre. Resistance was significantly correlated with antibiotic use in combination with day-care attendance. These findings warrant more judicious use of antibiotics in children.

Industry, air quality, cigarette smoke and rates of respiratory illness in Port Adelaide.

OBJECTIVES: To examine the prevalence of self-reported asthma, bronchitis/emphysema, wheezing, night cough and smoking in Port Adelaide; to explore the relationship of the disorders to the presence of industry, tobacco smoke, indoor appliances and air quality. METHODS: Prevalence data from a 1995 survey of Port Adelaide residents were compared with data from the 1995 National Health Survey and the 1995 South Australian Health Omnibus Survey. These data were then compared across three geographic areas in Port Adelaide, one being highly industrialised. Their relation to tobacco smoke and the presence of unflued gas appliances were examined. Finally, outdoor gaseous air pollutants were examined across the three areas. RESULTS: Males in Port Adelaide had higher rates of asthma and bronchitis/emphysema than nationally. Asthma was significantly higher for children aged 5-14 years and for adults aged 25-44 years. Bronchitis/emphysema was significantly higher for males aged 25-64. The highly industrial area had a higher rate of asthma (OR 1.85, 95% CI 1.07-3.22) in males that appeared unrelated to smoking or ambient gaseous pollutants. Smoking in Port Adelaide was significantly higher than in the general population, and was significantly associated with wheeze, night cough and bronchitis/emphysema. The presence of unflued gas heaters at home was significantly associated with asthma prevalence in males (OR 3.27, 95% CI 1.40-7.64). CONCLUSIONS: Respiratory disease appeared to be independently related to an area of high industry, smoking and presence of unflued gas appliances in Port Adelaide.

Respiratory effects associated with indoor nitrogen dioxide exposure in children.

BACKGROUND: The human health effects of exposure to indoor nitrogen dioxide (NO2) are unclear, and few studies have examined the effects of short-term peak levels of exposure. METHODS: The association between indoor exposure to NO2 and respiratory illness was examined in 388 children aged 6-11 years. The NO2 levels were monitored during winter in 41 classrooms, from four schools with unflued gas heating and four schools with electric heating. Each classroom was monitored daily with 6-hour passive diffusion badge monitors over nine alternate weeks, and with hourly monitors over two of those weeks. Children living in homes with unflued gas appliances were also monitored daily over four evenings during times of gas use. RESULTS: Exposure to NO2 at hourly peak levels of the order of > or = 80 ppb, compared with background levels of 20 ppb, was associated with a significant increase in sore throat, colds and absences from school. An increase in cough with phlegm was marginally significant. Significant dose-response relationships were demonstrated for these four measures with increasing levels of NO2 exposure. CONCLUSIONS: Short-term peak levels of exposure are important to consider in relation to adverse respiratory effects associated with NO2 exposure.

Identifying the active general practice workforce in one division of general practice: the utility of public domain databases.

OBJECTIVE: To identify the non-specialist medical practitioner workforce engaged in active general practice in the region served by the Division of General Practice-Northern Tasmania and to determine the usefulness of public domain databases for enumeration of individual non-specialists providing general practice services. METHODS: A masterlist of the active general practice workforce was compiled by obtaining the names and addresses/postcodes of all non-specialist medical practitioners who were listed in at least one of nine public domain databases and who were confirmed by selected local medical practitioners to be in active general practice in the three months prior to 30 June 1994. This masterlist was used in calculating the sensitivity and positive predictive value (PPV) of each of the nine databases for enumerating non-specialist practitioners in active general practice. RESULTS: Combining the databases resulted in a list of 475 practitioners, which was refined to 139 practitioners who, by our criteria, were in active general practice. Databases had a range of sensitivities and PPVs, but those with high sensitivity tended to have low PPVs, and vice versa. The most useful database for enumerating these practitioners was the mailing list for Australian Family Physician (sensitivity, 94%; PPV, 0.79). CONCLUSIONS: When used alone, no single database had both high sensitivity and high positive predictive value for identifying the active general practice workforce. Combining multiple databases may improve precision. Developing methods to identify recent departures from local active practice has the potential to improve the PPV of existing highly sensitive databases.

Health effects of exposure to cyanobacteria (blue-green algae) during recreational water-related activities.

The aim of this study was to investigate effects on health of exposure to cyanobacteria as a result of recreational water activities. Participants, who were aged six years and over, were interviewed at water recreation sites in South Australia, New South Wales and Victoria on selected Sundays during January and February 1995. Telephone follow-up was conducted two and seven days later to record any subsequent diarrhoea, vomiting, flu-like symptoms, skin rashes, mouth ulcers, fevers and eye or ear irritations. On the Sundays of interview, water samples from the sites were collected for cyanobacterial cell counts and toxin analysis. There were 852 participants, of whom 75 did not have water contact on the day of interview and were considered unexposed. The 777 who had water contact were considered exposed. No significant differences in overall symptoms were found between the unexposed and exposed after two days. At seven days, there was a significant trend to increasing symptom occurrence with duration of exposure (P = 0.03). There was a significant trend to increasing symptom occurrence with increase in cell count (P = 0.04). Participants exposed to more than 5000 cells per mL for more than one hour had a significantly higher symptom occurrence rate than the unexposed. Symptoms were not correlated with the presence of hepatotoxins. These results suggest symptom occurrence was associated with duration of contact with water containing cyanobacteria, and with cyanobacterial cell density. The findings suggest that the current safety threshold for exposure of 20,000 cells per mL may be too high.

Sequential continuity of care by general practitioners: which patients change doctor?

OBJECTIVE: To identify individual and social characteristics of patients making sequential visits to a different rather than the same general practitioner (GP). METHOD: Data for this study were extracted from the "Record Linkage Pilot Study" of the National Centre for Epidemiology and Population Health, which linked information from personal interviews with Health Insurance Commission and National Heart Foundation Risk Factor Survey data. Each sequence of visits (any two consecutive visits) made by each participant to the same or a different GP from January 1991 to December 1992 was treated as an event. PARTICIPANTS: 521 subjects aged between 23 and 72 years who gave consent to release of Health Insurance Commission data. MAIN OUTCOME MEASURE: A visit to the same GP or a different GP from the one seen at the last visit. RESULTS: Logistic regression analysis showed that younger age, good physical functioning, good self-rated health, normal body mass index, shiftwork and a longer time interval between visits were significantly associated with less continuity of care. CONCLUSIONS: Our study raises questions about the relationship between chronological continuity and quality of care. For example, if infrequent visits (associated with less continuity) are for distinct illnesses, is quality of care affected by information or treatment from a previous visit? Our results also suggest that some GPs, because of the demography of their practices (more young people, a higher proportion of shift workers), may be disadvantaged by continuity-based reward systems. Moreover, because of lack of continuity young people may miss out on GPs' health promotional activities.

Disinfection of drinking water, disinfection by-products and cancer: what about Australia?

Chlorine, commonly used to disinfect drinking water, produces by-products known from animal studies to be carcinogenic and mutagenic. Most epidemiological studies into the possible association between chlorination by-products in drinking water and cancer have been ecological in nature, or have relied on case-control designs based on death certificates. Interpretation of results arising from these studies is limited. Individual levels of toxicant exposure and many potential confounders and effect modifiers are unable to be accounted for in the analyses. At best, these studies generate hypotheses that require more definitive investigation. Misclassification of individuals based on inaccurate assessment of the level of exposure is probable. The few analytic studies able to overcome or minimise these problems suggest a clear link between exposure to chlorinated drinking water and the development of urinary bladder cancer. They also suggest a possible link with rectal cancer. However, these studies have classified subjects by exposure to chlorinated drinking water, rather than to levels of chlorine and its by-products in drinking water. To date, the link between levels of chlorine and its by-products in water, levels of consumption and cancer has not been made. Information on the levels of chlorine and some by-products is available in many water jurisdictions in Australia. Further, epidemiological methods can be employed to quantify water consumption. Case-control studies linking these parameters would help us to understand the magnitude of the risk to human populations and provide a basis to investigate mechanisms for risk reduction.

Indoor nitrogen dioxide and childhood respiratory illness.

Nitrogen dioxide is produced from the combustion of fossil fuels and as an emission from gas-fired appliances, and is also a component of tobacco smoke. Nitrogen dioxide has been shown in experimental animals to be toxic to the respiratory tract. A n number of recent studies have suggested that children exposed to significant levels of nitrogen dioxide in the home may be more susceptible to respiratory illness than children exposed to normal ambient levels. Respiratory illness is a major cause of morbidity in children everywhere. Here, we review the available evidence of this association and explore methodological issues in measurement of nitrogen dioxide exposure--misclassification of subjects, symptom bias and confounding. It has recently been shown that some New South Wales school rooms, where unflued gas heaters are often used as a source of warmth, have nitrogen dioxide levels which are above recommended ambient levels for outside air. This has underlined the need for setting standards for indoor levels of various pollutants, and cohort studies are suggested, to include personal monitoring and prospective data collection techniques.