Co-morbidity in general practice.

BACKGROUND: Co-morbidity, or the presence of more than one clinical condition, is gaining increased attention in epidemiological and health services research. However, the clinical relevance of co-morbidity has yet to be defined. In general practice, few studies have been conducted into co-morbidity, either at a single health care encounter, an episode of care, or for a defined time period. AIMS: To describe the major co-morbidity cluster profiles recorded by general practitioners. Another aim of this study is to describe the common clusters of co-prescribing. METHODS AND RESULTS: Twelve month data from patients attending 156 GPs from 95 practices around a six month period of January to June 2003 were analysed. This represented 840,961 encounters from about 200,000 individual patients at these participating practices. Co-morbidity and co-prescribing cluster profiles are represented by problems managed and reasons for prescribing for the top 10 presentations and top 10 prescribed drugs in the study period. CONCLUSIONS: By analysing the 10 most prevalent problems and 10 most prevalent drugs prescribed in consultations in a community sample, other co-morbidities that are particular to general practice, for example hypertension and lipid disorders, can be uncovered. Whether these clusters are causally related or occur by chance requires further analysis.

Immunocytochemical characterisation of the inflammatory cell infiltrate of varicose veins.

OBJECTIVES: To characterise the inflammatory cell infiltrate in varicose vein wall, and its relationship to the valve complex. DESIGN: A comparative study of the distribution of inflammatory cells in normal and varicose vein. MATERIALS: Specimens of proximal human long saphenous vein were obtained from patients with duplex Doppler confirmed long saphenous vein reflux (n=14). Control vein was obtained from patients undergoing coronary artery bypass without clinical evidence of venous insufficiency (n=6). Longitudinal 7 microm frozen sections of vein, displaying valve, were prepared. METHODS: Using immunohistochemistry, T-lymphocytes (CD3), macrophage/monocytes (CD68), neutrophils (CD15s) and mast cells (anti-mast cell tryptase) were identified. The number of cells per unit length vein were counted using light microscopy. RESULTS: There were significantly more mast cells and macrophage/monocytes in varicose vein as compared to control. There was a non-significant trend towards more T-lymphocytes in varicose vein. Few neutrophils were present in varicose or normal vein. The distribution of inflammatory cells with respect to the valve was not found to be significant. CONCLUSIONS: Varicose veins display a greater inflammatory cell infiltrate than normal vein. The key role of macrophage/monocytes and mast cells in tissue damage and remodelling should stimulate further research into whether they play a significant role in the development of chronic venous insufficiency.

Bisphosphonate use and subsequent prescription of acid suppressants.

AIM: To determine the extent of prescribing of acid suppression agents associated with initiation of bisphosphonate therapy. METHODS: This was a case control study, performed within the General Practice Network, Australia. The main outcome measure was re-attendance within six weeks from index bisphosphonate prescription for acid supression agents. RESULTS: Of the bisphosphonate cases, 2.9%[95% confidence interval (CI) 1.8, 3.9] returned within 6 weeks for a prescription for proton pump inhibitor, histamine 2 receptor antagonist or antacid, compared with 0.9% of control patients (95% CI 0.5, 1.2). However, the bisphosphonate cases had significantly higher rates of previous use of nonsteroidal anti-inflammatory agents. After controlling for previous nonsteroidal anti-inflammatory drug use, the increased use of acid suppression agents was statistically significant, the odds ratio = 3.21 (95% CI 2.02, 5.11). CONCLUSION: Bisphosphonate use appears to be associated with increased use of acid suppressant agents within 6 weeks of first supply.

Score of neonatal acute physiology as a measure of illness severity in mechanically ventilated term babies.

UNLABELLED: The objectives of this population-based, case-control cohort study were to describe the use of the score of neonatal acute physiology (SNAP) as a measure of illness severity in mechanically ventilated term infants, to compare the SNAP scores of the different diagnostic groups, to assess the contribution of the individual SNAP items to the overall SNAP severity category, and to assess SNAP as a predictor of mortality and neonatal intensive care unit (NICU) resource utilization (length of stay (LOS) and duration of ventilation (LOV)). The study was carried out in Sydney and four large rural/urban health areas in New South Wales, Australia. The subjects--182 singleton term infants with no major congenital anomalies--were admitted to a tertiary NICU for mechanical ventilation. Highest mean (SD) SNAP scores occurred in infants ventilated for meconium aspiration (18 (9)), and perinatal asphyxia (17 (9)), compared with pulmonary hypertension (14 (6)) and respiratory distress syndrome (13 (5)). The individual SNAP items that contributed most to SNAP moderate and severe categories were blood gas items, creatinine, urine output, blood glucose, and seizures. Predictors of death included total SNAP score, individual SNAP items (urine output, pH, Oxygenation Index (OI)), 5-min Apgar, gestational age >40 wk, growth restriction, and ventilation for asphyxia/apnoea. SNAP alone was not a good predictor of NICU resource utilization (LOS, LOV) in term infants. The best predictors were LOV for LOS, and a combination of SNAP and the reason for ventilation for LOV. CONCLUSION: SNAP is a useful measure of severity of illness in sick term neonates admitted to a tertiary NICU. This measure can be used to predict neonatal morbidity and mortality, and to some extent NICU resource utililization.

Reliability of the SNAP (score of neonatal acute physiology) data collection in mechanically ventilated term babies in New South Wales, Australia.

UNLABELLED: The aim of this population-based, case-control, cohort study was to report inter-rater reliability between the New South Wales Neonatal Intensive Care Unit Data Collection (NICUS) audit nurses' collection of SNAP (OS) and a research nurse's SNAP data as the audit SNAP (AS). The study was carried out in Sydney and four large rural/urban health areas in New South Wales (NSW), Australia. The subjects--182 singleton term infants with no major congenital anomalies--were admitted to a tertiary neonatal intensive care unit (NICU) for mechanical ventilation. SNAP data were collected on the 182 case infants, born between 1 January and 31 December 1996, by clinical audit officers in the nine tertiary NICUs in NSW. The research officer conducted an audit of the original SNAP score on all infants. The data were examined using Pearson's correlation coefficient, weighted kappa, a plot of difference in SNAP against mean SNAP and Wilcoxon's signed rank sum test. Pearson's correlation coefficient between the OS and AS data was 0.80. Median (interquartile range) SNAP was 13 (9,19) for the OS and 14 (10,20) for the AS. Weighted kappa was highest for highest heart rate, paO2, temperature (degrees C), oxygenation index, haematocrit, platelet count, lowest serum sodium, lowest blood glucose and seizure. In 17 (9%) infants, OS and AS differed by > or = 10, 14 because of an original data collection error, 1 data entry error, 1 audit error and 1 for both data collection and data entry errors. CONCLUSION: If SNAP is to be incorporated into any routine NICU data collection, it should be audited regularly on a sample of records. It is important to standardize and adhere to strict definitions for parameters before the collection of SNAP data.

Factors associated with low uptake of measles and pertussis vaccines--an ecologic study based on the Australian Childhood Immunisation Register.

OBJECTIVE: To evaluate the relationships between socio-economic and demographic variables and low immunisation coverage at the national level. METHODS: The Australian Childhood Immunisation Register (ACIR) contains data at the postcode level on the immunisation status of all children registered with Medicare under the age of seven years. The Australian Bureau of Statistics (ABS) produces a number of indicators of socio-economic status at the postcode level from Census data. These and other ABS demographic data were used to examine the relationship between immunisation coverage and various socio-demographic indicators. RESULTS: Factors associated with lower immunisation uptake differed in rural and metropolitan areas. High levels of education and occupation and a high proportion of Aboriginal residents were significantly associated with lower coverage only in metropolitan postcodes. High unemployment was associated with lower immunisation coverage only in rural postcodes. A high proportion of late starters to immunisation was the strongest single predictor of coverage and was important in rural and metropolitan postcodes. A high proportion of overseas-born persons and of GP-delivered immunisations was also associated with lower coverage in all areas. CONCLUSIONS: These data suggest that in metropolitan areas, reasons for low uptake in more advantaged areas require further evaluation. In non-metropolitan areas, low coverage was associated with areas of disadvantage, for which access to services may be more important. IMPLICATIONS: Children who are late in starting the schedule should be targeted.

Do very sick neonates born at term have antenatal risks? 1. Infants ventilated primarily for problems of adaptation to extra-uterine life.

AIMS: 1. Ascertain antenatal and intrapartum risk factors for term neonates ventilated primarily for 'perinatal asphyxia'. 2. Describe the neonatal morbidity and mortality. METHODS: Population-based case control cohort study. SETTING: Sydney and four large rural/urban health areas in New South Wales. SUBJECTS: Singleton term infants, no major congenital anomaly: subset of 83 infants ventilated primarily for 'asphyxia' from 182 cases admitted to a tertiary neonatal intensive care unit (NICU) for mechanical ventilation, 550 randomly selected controls. Outcome. Risk factors for case status by maternal, antenatal, labor, delivery, and combined epochs, adjusted odds ratios (OR), 95 per cent confidence intervals (CI), p < 0.05. RESULTS: Predictors of case status by multivariate epochs: Primigravida (1.8 [1.1, 2.8]), thyroid disease (7.8 [1.1, 57.0]), any antenatal complication (5.1 [3.0, 8.6]), growth restriction (4.2 [1.7, 10.4]), male gender (2.1 [1.3, 3.5]), gestational age >40 weeks (1.9 (1.1, 3.3)), prolonged rupture of membranes (9.7 [1.3, 72.5]), complicated labor (6.6 [3.7, 11.9]), induced labor (2.2 [1.3, 3.9]), prostaglandins 2.46 [1.23, 4.91]), maternal pyrexia (10.8 [2.8, 42.7]), placental hemorrhage in labor (OR 4.24 [1.45, 12.42]), forceps delivery (4.1 [1.9, 8.5]), emergency cesarean section (4.7 [2.6, 8.7]). Twenty case infants (24%) and no control infants died. CONCLUSIONS: This study has shown maternal and antepartum risk factors for severe neonatal morbidity in term infants. More centers need to become interested in the term baby, so that a larger multicenter study can further elucidate the heterogeneous causal pathways to term neonatal morbidity.

Do very sick neonates born at term have antenatal risks? 2. Infants ventilated primarily for lung disease.

AIMS: 1. Ascertain antenatal and intrapartum risk factors for term neonates ventilated primarily for respiratory problems. 2. Describe the neonatal morbidity and mortality. METHODS: Population-based case control cohort study. SETTING: Sydney and four large rural/urban Health Areas in New South Wales, 1996. SUBJECTS: Singleton term infants, no major congenital anomaly: subset of 99 infants ventilated primarily for respiratory problems from 182 cases admitted to a tertiary neonatal intensive care unit (NICU) for mechanical ventilation, and 550 randomly selected controls. OUTCOME: Risk factors for case status by maternal, antenatal, labor, delivery, and combined epochs, adjusted Odds Ratios (OR), 95 per cent Confidence Intervals (CI), p<0.05. RESULTS: Predictors of case status by multivariate epochs: mother's age > or =35 years (1.9 (1.1, 3.2) p=0.03), primigravida (1.8 (1.1, 2.8) p=0.01), any antenatal complication (3.8 (2.4, 5.9) p=0.0001), birth weight < 3rd percentile (3.7 (1.5, 9.1) p=0.006), gestational diabetes (2.9 (1.3, 6.9) p=0.01), maternal pyrexia (6.5 (1.6, 27.2) p=0.01), birth weight >90th percentile (1.8 (1.01, 3.2) p=0.047), gestation 37-38 weeks (2.3 (1.5, 3.6) p=0.0004), forceps (4.4 (2.1, 9.1) p=0.0001), elective cesarean section (3.7 (2.0, 6.5) p=0.0001), emergency cesarean section (4.5 (2.4, 8.4) p=0.0001). Case mortality rate was 5 per cent. CONCLUSION: The pathways to neonatal respiratory morbidity in term infants are multifactorial. Several areas which warrant more in-depth study are: elective cesarean section at 37-38 weeks gestation, fetal growth restriction, macrosomia and the pattern of in-utero growth, maternal weight gain during pregnancy, gestational diabetes, pyrexia in labor and the role of chorioamnionitis.

Measuring immunisation coverage in Australia. A review of the Australian Childhood Immunisation Register.

BACKGROUND: Before the establishment of the Australian Childhood Immunisation Register (ACIR), measurement of childhood immunisation coverage in Australia involved a variety of methods at varying intervals by general practice (GP) divisions, state health departments and the Australian Bureau of Statistics. Such surveys may underestimate (child health records) or overestimate (parental recall) true immunisation coverage. OBJECTIVE: The establishment of the ACIR in 1996 (a world first), was a huge undertaking involving 15,000 immunisation providers (60% GPs) notifying over 3 million immunisations annually. This review summarises the operation of the ACIR, how it calculates coverage, the accuracy of estimates from the ACIR and how Australia's immunisation coverage compares with that of other similar countries. Currently, the accuracy of the records on the register is questioned, especially in urban areas, but available data suggest that failure to report to the ACIR is the main source of data discrepancies. DISCUSSION: The ACIR has the potential to measure immunisation coverage at any practice or local level with accuracy and timeliness. With full provider participation, the ACIR is capable of identifying areas of low immunisation coverage for targeted interventions and will play a key role in the current measles campaign, the General Practice Immunisation Incentives scheme and in payments to parents. Achieving the highest possible completeness and timeliness of the ACIR is in the interests of providers, consumers and health planners.

Estimating and generalizing with clustered sampling in general practice.

General practice research focusing on patients may involve risk factors, morbidity, medication use or patient satisfaction. When collecting information about patients it is often easier, cheaper and more appropriate to enlist the support of a number of general practitioners (GPs) who provide access to a number of patients. Such studies utilise a 'cluster sampling' (CS) design, as clusters or groups of patients around a GP are used for the investigation. In analysing data from these studies it is necessary to consider the impact that the study design will have on the variance structure of data collected.

Sex differences in prescribed medications: another case of discrimination in general practice.

Biological, social and behavioural factors influence doctors to prescribe different types of medications to male and female patients. Secondary analysis of data from the Australian Morbidity and Treatment Survey 1990-1991 was conducted using multiple logistic regression to discriminate male and female patient encounters in general practice. The approach used considered possible confounding influences of GP and patient characteristics. The results showed that females were significantly more likely than males to receive prescriptions for: antibiotics; hormones; drugs affecting the central nervous, cardiovascular and urogenital systems; drugs for allergy and immune disorders; ear and nose topical preparations, and skin preparations, even after taking into account morbidity differences. If males and females were treated according to their presenting problems, differences in morbidity patterns would account for the management differences. However, the present investigation would suggest that GP and patient behaviours are also important factors that lead to differences in the prescriptions received by male and female patients in general practice.

Prediction of results from correspondence treatment for controlled drinking.

Identification of people who will benefit most from brief interventions is an important research challenge in the study of addictive disorders. The current study investigated predictors of response to correspondence interventions for alcohol abuse. We examined both subject retention and alcohol intake over a 12-month period. The primary focus was on the predictive utility of self-efficacy, stages of change and alcohol dependence. Self-efficacy performed relatively well in the study, predicting both retention and later consumption. When predicting 12-month consumption from pretest assessments or examining subject retention over the last 6 months, self-efficacy offered a significant contribution to multivariate analyses. However, in some other predictions a significant effect of self-efficacy was eliminated after the entry of other variables. Stages of change significantly predicted mid-way through treatment, but did not provide an independent prediction of overall retention or treatment response. Neither the degree of alcohol dependence nor level of alcohol problems figured in any of the predictions. Older subjects stayed longer in the study, and those with lower intake and higher pretest self-efficacy had the lowest consumption at 12 months. Results are compared with previous research on prediction of outcomes in addictive disorders.

The sex of the general practitioner: a comparison of characteristics, patients, and medical conditions managed.

In Australia an increasing proportion of active general practitioners (GPs) are women. Overseas research showing differences between male and female GPs in practice style, the reasons patients consult them, or in the nature of the medical conditions they manage has failed to adjust for confounders. In Australia, such differences have never been investigated. This study assessed differences between male and female GPs in terms of their personal characteristics, patient mix, patient reasons for consultation, and the medical conditions they manage. It also considered the extent to which differences are accounted for by the effect of confounders. A secondary analysis was done of data from the Australian Morbidity and Treatment Survey 1990 to 1991 (n = 113,000 general practice encounters). In addition, univariate analysis was followed by multivariate analysis, with adjustments for GP and patient characteristics and (in analysis of conditions managed) for patient reasons for encounter. Significant differences were found in the work patterns and patient mix of male and female GPs. Patients' selectivity in the problems presented to the two groups remained after adjustment for confounders. Female GPs managed more female-specific, endocrine, general, and psychosocial problems even after multivariate adjustment. Although male GPs managed more cardiovascular, musculoskeletal, male genital, skin, and respiratory problems at the univariate level, these differences were no longer apparent after adjustment. Male and female GPs manage different types of medical conditions. Although some differences are due to their patient mix and to patient selectivity, others are inherent to the sex of the physician. Extrapolation of results to Australian general practice suggests that these two groups of GPs could become semispecialized.

Immunisation in general practice. Results from the Australian Morbidity and Treatment Survey, 1990-1991.

Immunisation is the sixth most commonly managed problem in general practice in Australia. This paper provides an overview of its management in general practice.

Moderating drinking by correspondence: an evaluation of a new method of intervention.

Recognizing the need to offer alternative methods of brief interventions, this study developed correspondence treatments for low-dependent problem drinkers and evaluated their impact. One hundred and twenty-one problem drinkers were recruited by media advertisements and were randomly allocated to a full cognitive-behavioural treatment programme (CBT) or to a minimal intervention condition (MI) that gave information regarding alcohol misuse and instructions to record drinking++. As predicted, CBT was more effective than MI in reducing alcohol consumption over the 4-month controlled trial period. CBT produced a 50% fall in consumption, bringing the average intake of subjects within recommended maximum levels. Treatment gains at 6 months were well maintained to 12 months. High levels of consumer satisfaction, a high representation of women and a substantial participation from isolated rural areas attested to the feasibility of the correspondence programme as an alternative treatment. However, some drinking occasions still involved high intake for a significant subgroup of subjects, and this issue will be addressed in future programmes. The results supported the use of correspondence delivery as a means of promoting early engagement and equity of access between city and country areas.

Sex differences in morbidity: a case of discrimination in general practice.

Several factors influence sex differences in morbidity and general practice utilization rates. These factors are of a biological, social and behavioural nature and have differential effects on varying morbidity types. Secondary analysis of data from the Australian Morbidity and Treatment Survey 1990-91, was conducted using multiple logistic regression to discriminate female from male patient encounters in general practice. This approach considered possible confounding influences of GP and patient characteristics. The results showed there was a tendency for larger differences in the types of problems managed than in the types of reasons for encounter presented. Morbidity related to the reproductive, genitourinary and neurological systems, the blood, and of a psychological and social nature were significant contributors to female poor health and service utilization. Females were also more likely to present with digestive, cardiovascular and respiratory problems, while males were more likely to have digestive and cardiovascular problems managed. Furthermore, males were more likely to present skin complaints and have them managed. The potentially higher rates for males in cardiovascular, digestive, skin and respiratory morbidity not only reflect biological differences, but suggest differences in health reporting, utilisation and illness preventive attitudes.

Relative toxicity of beta blockers in overdose.

OBJECTIVE: To compare the toxicity of beta blockers in overdose and to identify clinical features predictive of serious toxicity. DESIGN: Comparison of clinical data collected prospectively on a relational database of subjects presenting to hospital with self-poisoning, coroner's data and prescription data. SETTING: Newcastle and Lake Macquarie, Australia, 1987-1995. MAIN OUTCOME MEASURES: Death, seizure, cardiovascular collapse, hypoglycemia, coma and respiratory depression. SUBJECTS: Fifty-eight self-poisonings with beta blockers and two deaths investigated by the coroner with evidence of propranolol poisoning. RESULTS: All patients who developed toxicity did so within six hours of ingestion. The use of ipecac was temporally associated with cardiorespiratory arrest in one patient. Propranolol was the only beta blocker associated with seizure; of those who ingested more than 2 g of propranolol, two thirds had a seizure. There was a significant association between a QRS duration of > 100 ms and risk of seizures. Propranolol was over represented in beta blocker poisoning when prescription data were also examined. Propranolol was the only beta blocker associated with death. Propranolol was taken by a younger age group. CONCLUSIONS: Propranolol should be avoided in patients at risk of self-poisoning. Propranolol poisonings should be observed closely for the first six hours post ingestion. Syrup of ipecac should not be used to decontaminate the gastrointestinal tract after beta blocker overdose.