Risk factors for isolated talipes equinovarus in Western Australia, 1980-1994

A case-control study based on routinely collected data for a West Australian (WA) cohort of births born 1980-94 inclusive was used to identify potential risk factors for the foot deformity isolated talipes equinovarus. Race and sex were identified as risk factors and risk modifiers of the condition in WA infants. In comparison with their female counterparts, Aboriginal males were at greater risk of the deformity than Caucasian males (odd ratio [OR] 7.15, 95% confidence interval [CI] 2.68, 21.12 vs. OR 1.63, 95% CI 1.24, 2.15 respectively). Sex-specific risk estimates of the deformity showed that Aboriginal males were at more than four times the risk of Caucasian males (OR 4.27, 95% CI 2.30, 8.25 respectively), but the risk amongst Aboriginal females was not dissimilar to the risk amongst Caucasian females (OR 1.12, 95% CI 0.49, 2.45). Intrauterine constraint of the fetus was not found to be an important contributing factor to the deformity after accounting for the effect of all risk factors modelled in multivariable analyses. Indicators of intrauterine constraint including prolonged gestation, high infant birthweight, young maternal age (< 20 years) and breech presentation were not associated with excess numbers of isolated talipes equinovarus cases. Limited numbers of cases associated with other indicators of intrauterine constraint, including the specific categories of short maternal stature and a twin pregnancy prevented definitive conclusions regarding their association with the deformity. Improved data quality for gestational age estimates and oligohydramnios status are required before determining the prenatal risk impact of season of conception and of reduced amniotic fluid levels, respectively, on the occurrence of the deformity.

Readability and content of supplementary written drug information for patients used by Australian rheumatologists

OBJECTIVE

To determine the readability and content of supplementary written drug information currently being given to patients by rheumatologists in Australia.

DESIGN AND PARTICIPANTS

Blinded standardised review by two independent reviewers of supplementary written drug information routinely provided to patients by the 195 fully registered members of the Australian Rheumatology Association (ARA).

MAIN OUTCOME MEASURES

FOG and SMOG readability scores to estimate readability; critical appraisal of content according to predetermined criteria.

RESULTS

84 rheumatologists responded (43%), 45 of whom reported providing copies of written drug information to patients. Overall, 91 different documents were reviewed. Drugs most commonly considered were methotrexate (17), gold (16), sulfasalazine (10), penicillamine (10) and prednisolone (8). Level of agreement between reviewers for FOG and SMOG scores was fair to good (intraclass correlation coefficient, 0.61 and 0.51, respectively). Mean (95% CI) FOG and SMOG scores were 12.6 (12.2-12.9) and 11 (10.7-11.2), respectively (implying that half of those in Year 12 [or aged 17 years] and Year 11 [or aged 16 years] according to the FOG and SMOG mean scores, respectively, will comprehend half of the text or more). For the same medication, there was a wide variation in the information provided, including which side effects were discussed. While 98% included some information about side effects, fewer considered dose (74%), drug interactions if applicable (70%), purpose of drug (67%), how and when to take the drug (62%), expected time to improvement (54%), what to do in the event of side effects (44%), the expected duration of therapy (18%) and what to do if a dose was missed (5%).

CONCLUSIONS

The reading level required to understand supplementary written drug information used by Australian rheumatologists is much higher than the average reading ability of the Australian population (estimated at Year 8 level). The content of this information varies widely and often omits important information.

Longterm methotrexate use in rheumatoid arthritis: 12 year followup of 460 patients treated in community practice

OBJECTIVE

To extend our observations on the longterm tolerability of methotrexate (MTX) and reasons for discontinuation in a cohort of 460 patients with rheumatoid arthritis (RA).

METHODS

We studied all patients with RA who started MTX before June 1986 and attended the community based private practices of 6 rheumatologists in Melbourne. Information to at least April 1, 1995, or within one year of death was updated from the patient's medical records to include MTX discontinuation and reasons for discontinuation. Addition of disease modifying antirheumatic drugs (DMARD) concomitant with MTX was noted. Survival analyses based upon life table methods were used with MTX discontinuation as the observable endpoint. Three different definitions of MTX discontinuation were used (1) according to whether the patient was taking the drug at last followup irrespective of any periods of temporary discontinuation; (2) MTX discontinuation for > 3 months considered to be a treatment endpoint; and (3) addition of concomitant DMARD considered to be only partial success of MTX (as a need for additional therapy to meet treatment goals).

RESULTS

At 12 years, 53% of patients were continuing to take MTX (irrespective of any periods of temporary discontinuation). If discontinuation of the drug for 3 or more months was considered a treatment termination then 38% were still taking the drug at 12 years, and if addition of concomitant DMARD was regarded as a treatment endpoint only 17% of patients were continuing MTX at 12 years. Withdrawal for gastrointestinal toxicity declined over time but the risk of other adverse effects appeared to persist over time.

CONCLUSION

MTX in RA is well tolerated over the longer term, with > 50% of patients starting MTX in a community based rheumatology private practice continuing to take it 12 years later. However, a substantial number of patients had 2nd line therapies added over this time. Monitoring for toxicity should continue throughout the course of therapy.

Diabetes incidence in an Australian aboriginal population. An 8-year follow-up study

OBJECTIVE

To examine prospectively the association between age, BMI, and subsequent incidence of type 2 diabetes in Australian aboriginal people.

RESEARCH DESIGN AND METHODS

We performed a stratified analysis of incidence data from a community-based longitudinal study. Measures included fasting and 2-h postload glucose concentrations, and BMI, stratified into four categories. Subjects were 882 male and female participants in diabetes screening initiatives in two remote Australian aboriginal communities, free from diabetes at baseline, ages 15-77 years.

RESULTS

There were 46 incident cases of diabetes over 2,808 person-years of follow-up. BMI modified strongly the sex- and community-adjusted association between age and diabetes incidence (P < 0.001). Adjusted for age, sex, and community, the population diabetes incidence rate was 20.3 cases/1,000 person-years, with BMI-specific rates of 10.7-47.2 cases/1,000 person-years, and relative risks (95% CI) for BMI strata beyond the reference category (< 25 kg/m2) of 3.3 (1.5-7.0), 2.7 (1.1-6.8), and 4.4 (1.7-11.6), respectively. The population's attributable risk (95% CI) associated with BMI beyond the reference category was 70.1% (58.1-82.4).

CONCLUSIONS

BMI-specific diabetes incidence rates in Australian aboriginal people are among the highest in the world. Diabetes incidence in the lowest BMI category (10.7 cases/1,000 person-years) is two to five times greater than corresponding rates for non-aboriginal populations. An urgent need exists to prevent weight gain associated with diabetes. Further study is required to determine for aboriginal people an optimal range of BMI, likely lower than that suggested for non-aboriginal populations.

Occupational risk factors for Alzheimer disease: a case-control study

There is evidence to support the role of a number of environmental factors in Alzheimer disease (AD). This study examines the role of chemical and physical exposures in the occupational environment. The sample included 170 patients with AD and 170 medical-practice-based controls, matched for age and sex, who were assessed for histories of occupational exposures to a range of chemical and physical agents, including hydrocarbon solvents, lead, mercury, organophosphates, aluminum, asbestos and other silicates, vibration, and physical underactivity. Occupational histories were obtained from informants for both patients and controls. Exposure was assessed by a panel of occupational hygienists, blinded to the case or control status of each subject, using the occupational histories and the Job-Exposure Matrix of the U.S. National Institute for Occupational Safety and Health. No statistically significant associations were found between any of the exposures and the occurrence of AD, either in the overall study group or in patients with a family history of AD. The findings suggest the absence of any occupational cause for AD.

Radon daughter exposures at the Radium Hill uranium mine and lung cancer rates among former workers, 1952-87

The aim of this historical (retrospective) cohort study was to investigate the relation between occupational exposure to radon daughters and subsequent mortality from lung cancer. Participants were former workers from the Radium Hill uranium mine, which operated in eastern South Australia from 1952 to 1961. A total of 2,574 workers were identified from mine records. Exposures to radon daughters were estimated from historical records of radon gas concentrations in the mine and from individual job histories. Exposures of underground workers were low by comparison with other mines of that period (mean 7.0 Working Level Months [WLM], median 3.0 WLM). Thirty-six percent of the cohort could not be traced beyond the end of employment at Radium Hill. Among those traced to the end of 1987, lung cancer mortality was increased relative to the Australian national population of the period (Standardized Mortality Ratio = 194, 95 percent confidence interval [CI] = 142-245). Compared with surface workers, lung cancer mortality was markedly increased in the underground workers with radon daughter exposures greater than 40 WLM (relative risk = 5.2, CI = 1.8-15.1). From the available information, we conclude that this increase is unlikely to be due to differences in smoking habits or other confounders. Taken together with the findings from other occupational studies, these results support current moves towards more stringent radiation control in the workplace, and underline the importance of research into the possible effects of domestic radon exposures.

HIV prevalence and risk behaviours for HIV transmission in South Australian prisons

During the latter half of 1989, HIV prevalence in South Australian prisoners was 1.4%. The prevalence of HIV infection across the prison system did not change significantly during 1989 but there was clustering of HIV-infected prisoners in some prisons. Almost half the prisoners from all of the South Australian prisons agreed to participate in our studies, from which we estimate that about 42% of prisoners engage in risk behaviours at least once while incarcerated. Prisoners estimated that 36% of all prisoners inject drugs intravenously at some stage during their stay and that 12% engage in anal intercourse at least once. Interviews with former prisoners who had a history of intravenous drug use revealed that about half had injected themselves while in prison, 60% shared needles and most did not clean shared needles adequately. Most of these prisoners injected themselves once a month or less frequently. The conditions for spread of HIV within the prison system exist but at the current prevalence of infection, transmission can be expected to be infrequent. The opportunity exists now to improve and expand preventive measures.

Relationship between milk intake and mucus production in adult volunteers challenged with rhinovirus-2

In the first of three studies investigating the widely held belief that "milk produces mucus," 60 volunteers were challenged with rhinovirus-2, and daily respiratory symptoms and milk and dairy product intake records were kept over a 10-day period. Nasal secretion weights were obtained by weighing tissues collected and sealed immediately after use. Information was obtained on 51 subjects, yielding 510 person-days of observation. Subjects consumed zero to 11 glasses of milk per day (mean, 2.7; SE, 0.08), and secretion weights ranged from zero to 30.4 g/day (mean, 1.1; SE, 0.1). In response to an initial questionnaire, 27.5% reported the practice of reducing intake of milk or dairy products with a cold or named milk or dairy products as bad for colds. Of the latter group, 80% stated the reason as "producing more mucus/phlegm." Milk and dairy product intake was not associated with an increase in upper or lower respiratory tract symptoms of congestion or nasal secretion weight. A trend was observed for cough, when present, to be loose with increasing milk and dairy product intake; however, this effect was not statistically significant at the 5% level. Those who believe "milk makes mucus" or reduce milk intake with colds reported significantly more cough and congestion symptoms, but they did not produce higher levels of nasal secretions. We conclude that no statistically significant overall association can be detected between milk and dairy product intake and symptoms of mucus production in healthy adults, either asymptomatic or symptomatic, with rhinovirus infection.

Transcutaneous bilirubinometry in preterm very low birthweight infants

Transcutaneous bilirubinometry using the Minolta Airshield TcB was performed on 40 preterm VLBW Chinese infants during the first 7 days of life; altogether 614 observations were made on the forehead and sternum, respectively. A positive correlation between the TcB index and plasma bilirubin concentration was obtained on the forehead and sternum. Positive plasma bilirubin-TcB index correlations were also observed for each individual day. The plasma bilirubin-TcB index (forehead) regressions were fairly similar for the individual days and the combined overall regression except for 2 days (days 5 and 7). A slight improvement was observed when only bilirubin concentrations less than or equal to 200 mumol/l were evaluated. The intercepts were however different for individual days requiring correction factors to the combined overall regression intercept if the regression is to be used for the respective days. However, the plasma bilirubin-TcB index (sternum) regression for the individual days were significantly different one from another, and from the overall combined plasma bilirubin-TcB index (sternum) regression. This significant difference was still observed when only plasma bilirubin concentrations less than or equal to 200 mumol/l were evaluated. Hence, transcutaneous bilirubinometry has major limitations in preterm VLBW infants.

alpha-Fetoprotein levels in fullterm and very low birthweight infants

Plasma alpha-fetoprotein (alpha-FP) levels were determined in fullterm and very low birthweight (VLBW) infants in the first week of life and serially in a cohort of VLBW infants for the first 24 weeks after delivery. A rapid decline in alpha-FP levels was observed in both the fullterm and VLBW infants initially. Beyond 2 weeks of age, there was a gradual, linear decline until 6 weeks, followed by a more rapid period of decline from 6 to 16 weeks. The decline in the ensuing weeks demonstrated an asymptotic pattern. The half-life of alpha-FP was 7.5 days in the first week of life in both fullterm and preterm infants, 28.7 days from 2 to 6 weeks of life and 11.9 days from 6 to 16 weeks of life in VLBW infants.