The burden of end-stage osteoarthritis in Australia: a population-based study on the incidence of total knee replacement attributable to overweight/obesity

OBJECTIVES

To determine the risk of total knee replacement (TKR) for primary osteoarthritis (OA) associated with overweight/obesity in the Australian population.

METHODS

This population-based study analyzed 191,723 cases of TKR collected by the Australian Orthopaedic Association National Joint Registry and population data from the Australian Bureau of Statistics. The time-trend change in incidence of TKR relating to BMI was assessed between 2015 and 2018. The influence of obesity on the incidence of TKR in different age and gender groups was determined. The population attributable fraction (PAF) was then calculated to estimate the effect of obesity reduction on TKR incidence.

RESULTS

The greatest increase in incidence of TKR was seen in patients from obese class III. The incidence rate ratio for having a TKR for obesity class III was 28.683 at those aged 18-54 years but was 2.029 at those aged >75 years. Females in obesity class III were 1.7 times more likely to undergo TKR compared to similarly classified males. The PAFs of TKR associated with overweight or obesity was 35%, estimating 14,287 cases of TKR attributable to obesity in 2018. The proportion of TKRs could be reduced by 20% if overweight and obese population move down one category.

CONCLUSIONS

Obesity has resulted in a significant increase in the incidence of TKR in the youngest population in Australia. The impact of obesity is greatest in the young and the female population. Effective strategies to reduce the national obese population could potentially reduce 35% of the TKR, with over 10,000 cases being avoided.

Incidence and associated risk factors for falls in adults with intellectual disability

BACKGROUND

People with intellectual disability (ID) experience age-related changes earlier in life, and as such, falls among people with ID are of serious concern. Falls can cause injury and consequently reduce quality of life. Limited studies have investigated the incidence of falls among people with ID and the associated risk factors. The purpose of this study was to investigate the incidence of falls and risk factors for falling in people with ID living in the community.

METHODS

A prospective observational cohort (n = 78) of community-dwelling adults with ID. Characteristics measured at baseline included falls history, medication use, balance and mobility. Falls were reported for 6 months using monthly calendars and phone calls. Data were analysed using univariate and multivariate logistic regression to identify risk factors associated with falling.

RESULTS

Participants [median (interquartile range) age 49 (43-60) years, female n = 32 (41%)] experienced 296 falls, with 36 (46.2%) participants having one or more falls. The incidence of falls was 5.7 falls (injurious falls = 0.8) per person year (one outlier removed from analysis). A history of falls [adjusted odds ratio (OR): 6.37, 95% confidence interval (CI) (1.90-21.34)] and being ambulant [adjusted OR: 4.50, 95% CI (1.15-17.67)] were associated with a significantly increased risk of falling. Falls were significantly less frequent among participants taking more than four medications [adjusted OR: 0.22, 95% CI (0.06-0.83)] and participants who were continent [adjusted OR: 0.25, 95% CI (0.07-0.91)].

CONCLUSIONS

People with ID fall at a younger age compared with the broader community. The associated falls risk factors also differ to older community-dwelling adults. Health professionals should prioritise assessment and management of falls risk in this population.

P2440Increased mortality with high versus normal ejection fraction in elderly women

Methods

NEDA contains echo data (>530,000, years 1997–2017) from laboratories (N=14) across Australia, linked to the National Death Index (NDI). 331,344 individuals aged >18 years (n=172,251 [52%] men, age=60.8±18.0 years and 152,095 [48%] women, 60.9±19.2 years) had a mean follow up of 5.4 person-years and 63,142 fatal events. LVEF using Method Of Discs (MOD) could be calculated in 116,544 individuals. We compared mortality in those with normal LVEF (52–72% for males and 54–74% for females) compared with high LVEF (>72% and >74% for males and females, respectively).

Results

Mortality was 11% higher in females with high LVEF vs females with normal LVEF. On multivariable logistic regression, high ejection fraction remained an independent predictor of mortality after correction for age, gender and body mass index. High LVEF was positively associated with female gender, age and diastolic dysfunction. Of 96,033 individuals in the study population, there were 46,876 males (48.8%), mean age 61.19±17.09 years, not significantly different from their female counterparts. 44,282 males had normal LVEF (52–72%) as opposed to 2,594 with high LVEF (>72%). In females, 46,186 had normal LVEF (54–74%) and 2,971 had high LVEF.InCox proportional hazard models, the hazard ratio (HR) for mortality in males with normal EF was 1.105 for age (95% CI 1.102 to 1.07) and 1.074 (95% CI 0.988 to 1.167) for high LVEF (p<0.001 for all outputs). In females, the corresponding adjusted HR was 1.107 for age (95% CI 1.105 to 1.110) and 1.140 for high LVEF (95% CI 1.057 to 1.230).

Conclusion

High LVEF, particularly in older women, is associated with increased mortality compared with an LVEF within the reference range. Further study is required to evaluate possible mechanisms for worse outcomes in patients with high LVEF.

Current Practice of Therapeutic Hypothermia for Mild Hypoxic Ischemic Encephalopathy

CONTEXT

Therapeutic hypothermia is the recommended treatment for neonates with moderate or severe hypoxic ischemic encephalopathy (HIE). There is an increasing trend to use therapeutic hypothermia even in infants with mild hypoxic ischemic encephalopathy, even though there is little evidence to support/refute this.

OBJECTIVE

To estimate the incidences of mild hypoxic ischemic encephalopathy among infants who received therapeutic hypothermia, and its short- and long-term outcomes.

DATA SOURCES AND STUDY SELECTION

PubMed, Embase, CINAHL, and Cochrane library were searched to identify observational studies reporting on therapeutic hypothermia in term and near-term infants with mild hypoxic ischemic encephalopathy. The JBI (Joanna Briggs Institute) tools were used to assess the risk of bias in the included studies. Random effects meta-analysis was conducted to find out the percentage of cooled infants who had only mild hypoxic ischemic encephalopathy.

RESULTS

A total of 3590 citations were screened, of which 13 were included. Of the 2783 infants who received therapeutic hypothermia, 573 had mild hypoxic ischemic encephalopathy. Meta-analysis found that 22% of the infants who underwent therapeutic hypothermia had only mild hypoxic ischemic encephalopathy (95% confidence interval: 16%-27%; I² statistic = 90.5%). Five studies provided information on adverse effects of therapeutic hypothermia in mild hypoxic ischemic encephalopathy. The reported adverse effects were extreme hypothermia, bradycardia, hypoglycemia, sepsis, skin necrosis, pulmonary hypertension, and systemic hypotension. Limitation: The limitations included relatively small sample size and the lack of data for short- and long-term neurodevelopmental outcome.

CONCLUSIONS

A significant proportion of infants who received therapeutic hypothermia had mild hypoxic ischemic encephalopathy. Randomized trials are urgently needed to evaluate the efficacy and safety of therapeutic hypothermia in infants with mild hypoxic ischemic encephalopathy.

Abstract P1-09-08: Does adverse tumour biology contribute to inferior outcomes for Indigenous Australians diagnosed with breast cancer?

Background: Analyses across multiple Australian states have consistently demonstrated significantly inferior breast cancer survival for Indigenous patients (IPs). Studies compensating for increased remoteness, socioeconomic disadvantage and later presentation demonstrate a residual unexplained detriment. This survival disadvantage is confined to the first five years, akin to the inferior outcomes demonstrated by higher risk biological breast cancer subtypes. We postulated that a preponderance of such higher risk subtypes could explain the disparate mortalities.

Methods: The distribution of breast cancer subtypes in Western Australian IPs diagnosed between 2001 and 2010 was assessed to explore the contribution of adverse prognostic subtypes to poorer outcome. This was a retrospective cohort study of Indigenous women (n=114) and 3:1 age and remoteness matched non-Indigenous women (n=310) diagnosed with invasive, non-metastatic, unilateral breast cancer, who underwent definitive local treatment. Subtypes were assigned as luminal A, B, HER2 enriched and triple negative by ER, PR, HER2 and tumour grade comparisons. Differences in basic tumour demographics and biological sub-types were analysed and racial survival discrepancies explored within biological subtype cohorts.

Results: Hazards for overall and breast cancer-specific mortality in IPs were 4.07 (95% CI 2.55-6.49) and 4.19 (95% CI 2.42-7.25). IPs were significantly more likely to have grade 3 tumours (41 v 25%, p&lt;0.001), LN positive disease (39 v 27%, p&lt;0.001) and larger tumours (median 20 v 10 mm, p&lt;0.001). No significant differences in proportions of classical histological sub-types (ductal v lobular) or in tumours showing ER, PR or HER2 positivity were observed. There were no significant differences in biological sub-type proportions although IPs were diagnosed with numerically more non-Luminal A subtypes (56 v 44%, p=0.08), accounted for by increased Luminal B (21 v 15%) and HER2 enriched (10 v 5%) sub-types. The significant relative five-year survival deficit for IPs noted overall (94 v73%, p&lt;0.0001) was observed for each sub-type with the exception of HER2 positive patients. This extended from the relatively low risk luminal A sub-type where oral anti-estrogens are the mainstay of treatment (98 v 82%, p=0.0002) to the high risk triple negative sub-type where intravenous chemotherapy is the standard adjuvant therapy (94 v 50%, p=0.0014).

Conclusions: The contribution of adverse tumour biological subtype to poorer outcomes for Indigenous women is modest. Indigenous women with almost all biological subtypes fare significantly worse than their non-Indigenous contemporaries. Ongoing work includes more detailed biological comparisons of RNA expression and DNA mutation between groups as well as an exploration of potentially disparate treatment patterns.

Citation Format: Redfern A, Lee E, Bulsara M, Threlfall T, Harvey J, Cordell D. Does adverse tumour biology contribute to inferior outcomes for Indigenous Australians diagnosed with breast cancer?. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-09-08.

Clinical indicators for the initiation of endotracheal suction in children: An integrative review

BACKGROUND

Critical decisions and interpretation of observations by the nurse caring for the paediatric intensive care (PIC) patient can have dramatic and potential adverse impact on the clinical stability of the patient. A common PIC procedure is endotracheal tube (ETT) suction, however there is inconsistent evidence regarding the clinical indicators to guide and support nursing action. Justification for performing this procedure is not clearly defined within the literature. Further, a review of the literature has failed to establish clear standards for determining if the procedure is warranted, especially for paediatric patients.

OBJECTIVE

The objective of the review is to identify current clinical indicators used in practice to determine why ETT suction should be performed.

METHOD

An integrative review using a systematic approach to summarise the empirical and theoretical evidence within the literature as it relates to clinical practice was used.

RESULTS

Consensus of opinion indicates that ETT suctioning should only be performed when clinically indicated. There is no general consensus regarding which clinical indicators should be measured and used to guide the decision to perform ETT suctioning.

CONCLUSION

Research is required to identify the clinical indicators that could be used to design a valid and clinically appropriate tool to use to assist in the decision making process to perform ETT suction.

Abstract P1-13-16: Women commencing with anastrozole, letrozole or tamoxifen: The impact of comorbidity and demographics on initial choice

Background: Australian clinical guidelines recommend post-surgical endocrine therapy for all women with early, hormone-dependent breast cancer. Guidelines specify tamoxifen as first-line therapy for pre-menopausal women, and either tamoxifen or an aromatase inhibitor for post-menopausal women depending on their risk of recurrence which is based on tumour size and other prognostic indicators. Tamoxifen and the aromatase inhibitors have different side effect profiles and therefore comorbidity may also influence choice of therapy. We examined comorbidities, and the clinical and demographic characteristics of women initiated on different endocrine therapies for breast cancer in Australian practice.

Method: We identified the first dispensing of tamoxifen, anastrozole or letrozole for women diagnosed with invasive breast cancer in the 45 and Up Study between January 2003 and December 2009 (n = 1383). Unit-level pharmacy and medical service claims, hospital separations, and Cancer Registry records were linked to self-reported data to determine menopause status at diagnosis, tumour size, age, change in subsidy restrictions, and specified comorbidities which may affect choice of therapy (i.e. arthritis, endometrial cancer, osteoporosis, thromboembolism). Chi-square tests and multivariate generalised linear models were used to compare the characteristics of post-menopausal women initiated on different therapies.

Results: The majority of pre-menopausal women commenced therapy with tamoxifen (93%). Tamoxifen was the predominant therapy for post-menopausal women with tumours ≤1cm (54%), and anastrozole most common for those with larger tumours (49%). Post-menopausal women with osteoporosis were less likely to commence an aromatase inhibitor compared with tamoxifen (anastrozole RR = 0.7, 95%CI = 0.5-0.9, P = 0.019; letrozole RR = 0.6, 95%CI = 0.3-0.9, P = 0.033) and those with arthritis were 1.6-times more likely to commence with letrozole than anastrozole (95%CI = 1.6-2.3, P = 0.004). Tamoxifen was more likely to be initiated in women with large tumours who also had comorbid arthritis or were aged ≥75 years. Changes in subsidy restrictions were associated with significant increases in the proportion of post-menopausal women commencing an aromatase inhibitor rather than tamoxifen (anastrozole RR = 7.0; letrozole RR = 18.5).

Conclusions: The findings show clinical guidelines regarding endocrine therapies are being followed in Australian practice, particularly in relation to menopause status and tumour size as a recurrence risk factor. The findings also indicate there is interplay of comorbidity and choice of therapy for older women and those with arthritis or osteoporosis.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-13-16.

Abstract P5-14-12: Cosmetic outcome is better after intraoperative radiotherapy compared with external beam radiotherapy: An objective assessment of patients from a randomized controlled trial

The randomised controlled TARGeted Intraoperative radioTherapy (TARGIT) Trial has demonstrated non-inferiority between the novel technique of TARGIT (intra-operative radiotherapy with Intrabeam ®) and conventional whole-breast external beam radiotherapy (EBRT) in women with early breast cancer, in terms of the primary outcome measure of risk of local relapse within the treated breast. As there are very low recurrence rates, cosmesis becomes an increasingly important outcome of breast conserving treatment with both surgery and radiotherapy. This study was performed to determine if the single high dose of TARGIT compared with EBRT leads to impaired cosmesis.

A validated, objective assessment software tool for evaluation of cosmetic outcome was used. Frontal digital photographs were taken at baseline (before radiotherapy) and annually thereafter for up to five years. The photographs were analysed by BCCT.core which produces a composite score based on symmetry, colour and scar.

A total of 342 patients were assessed, all over 50 years old with a median age at baseline of 64 years (IQR 59 to 68). The BCCT.core scores were dichotomised into Excellent and Good (EG), and Fair and Poor (FP). There were statistically significant increases in the odds of having an outcome of EG for patients in the TARGIT group compared with the EBRT group at year 1 (OR = 2.07, 95%CI 1.12 to 3.85, p = 0.021) and year 2 (OR = 2.11, 95%CI 1.0 to 4.45, p = 0.05).

This objective assessment of aesthetic outcome in patients from a randomised setting demonstrates that those treated with targeted intraoperative radiotherapy have a superior cosmetic result compared with those patients who received conventional whole-breast external beam radiotherapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-12.

Intrinsic to extrinsic phonon lifetime transition in a GaAs-AlAs superlattice

We have measured the lifetimes of two zone-center longitudinal acoustic phonon modes, at 320 and 640 GHz, in a 14 nm GaAs/2 nm AlAs superlattice structure. By comparing measurements at 296 and 79 K we separate the intrinsic contribution to phonon lifetime determined by phonon-phonon scattering from the extrinsic contribution due to defects and interface roughness. At 296 K, the 320 GHz phonon lifetime has approximately equal contributions from intrinsic and extrinsic scattering, whilst at 640 GHz it is dominated by extrinsic effects. These measurements are compared with intrinsic and extrinsic scattering rates in the superlattice obtained from first-principles lattice dynamics calculations. The calculated room-temperature intrinsic lifetime of longitudinal phonons at 320 GHz is in agreement with the experimentally measured value of 0.9 ns. The model correctly predicts the transition from predominantly intrinsic to predominantly extrinsic scattering; however the predicted transition occurs at higher frequencies. Our analysis indicates that the 'interfacial atomic disorder' model is not entirely adequate and that the observed frequency dependence of the extrinsic scattering rate is likely to be determined by a finite correlation length of interface roughness.

P3-13-07: The TARGIT-A Trial Update Confirms No Increase in Local Recurrence

Introduction: In June 2010, we published the results of the TARGIT-A trial (1) that compared “one-size fits” all radiotherapy (whole breast radiotherapy-EBRT group) with risk -adjusted radiotherapy (TARGIT- group: single dose TARGeted Intraoperative radioTherapy with additional whole breast radiotherapy if adverse prognostic factors were found). These results showed that the risk of local recurrence in the TARGIT group was non-inferior to that of the EBRT group (the difference between the two arms was 0.25% at 4 years). We now report the results analyzed after further follow up of the total trial cohort without unblinding.

Method: As often repeated, unplanned analysis comparing two groups in a randomized trial can result in an increased alpha-spent as well as carry the risk of a false positive result, we have remained blinded to the further recurrences in the trial according to allocated treatment, since the original publication in the Lancet. Instead we proposed and performed a blinded analysis of the local recurrence rate for the whole cohort. We plotted the Kaplan Meier plots and compared the estimated 4-year recurrences.

Results: Amongst the 2232 patients randomized, there were 13 recurrences at the time of Lancet publication and since then, we have had 8 additional recurrences. The number of patients who have completed at least 4 years of follow up has increased from 420 to 717. We found that the 4-year Kaplan Meier estimate of local recurrence was 1.08% (95% CI 0.59 −1.96) at the time of the Lancet publication and it is 1.09% (95% CI 0.65 - 1.85) now.

Conclusion: We found that the overall 4-year recurrence rates of the TARGIT-A trial have remained stable with a longer follow up and therefore; it is statistically implausible, that one particular arm has a significantly higher local recurrence.

References

1. Vaidya JS, Joseph DJ, Tobias JS, Bulsara M, Wenz F, Saunders C, Alvarado M, Flyger HL, Massarut S, Eiermann W, Keshtgar M, Dewar J, Kraus-Tiefenbacher U, Sutterlin M, Esserman L, Holtveg HM, Roncadin M, Pigorsch S, Metaxas M, Falzon M, Matthews A, Corica T, Williams NR, Baum M. Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial): an international, prospective, randomised, non-inferiority phase 3 trial. Lancet 2010;376(9735):91–102.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-13-07.

Cosmetic outcome 1, 2, 3, and 4 years after intraoperative radiotherapy or external beam radiotherapy for early breast cancer: An objective assessment of patients from a randomized controlled trial

94

Background: The randomized controlled TARGIT Trial was designed to determine noninferiority between the novel technique of TARGIT [intra-operative radiotherapy with Intrabeam (Carl Zeiss, Germany)] and conventional external beam radiotherapy (EBRT) in women with early breast cancer. The main outcome objective is risk of local relapse within the treated breast. We report here data from a subprotocol assessing cosmesis in 114 women over 50 years old participating in the TARGIT Trial from one center (Perth, Australia).

Methods: Frontal view digital photographs from were assessed, blind to treatment, using specialist software (BCCT.core 2.0, INESC Porto, Portugal) that produces an objective composite score based on symmetry, color, and scar. Data on patient and tumor characteristics were obtained from hospital notes. Statistical analysis was by generalized estimating equations (GEE) on all data, and logistic regression analysis at year 1 only.

Results: Photographs were taken at baseline (before surgery) and 1, 2, 3, and 4 years after initial breast-conserving surgery; none of the 114 patients had subsequent breast surgery. Median age at randomization was 62 years (IQR 56 to 68). The composite scores were dichotomized into Excellent and Good (EG), and Fair and Poor (FP). There was a nonsignificant 45% increase in the odds of having an outcome of EG for patients in the TARGIT group relative to the EBRT group (OR=1.45, 95%CI 0.78 – 2.69, p=0.245) after adjusting for tumour size. The results were similar when adjusted for tumor grade and age of the patient. For year 1 there was a statistically significant 2.35 fold increase in the odds of having an outcome of EG for patients in the TARGIT group relative to the EBRT group (OR=2.35, 95%CI 1.02 – 5.45, p=0.047) after adjusting for age of the patient, tumor size, and grade.

Conclusions: These results confirm a significantly better cosmetic outcome with TARGIT compared to EBRT in the first year after surgery.

Knowledge and perceptions regarding oral and pharyngeal carcinoma among adult dental patients

BACKGROUND

The aim of this study was to assess awareness and knowledge of oral and pharyngeal carcinoma and risk perception for developing the cancer among adult patients attending a major dental centre in Perth. Influence of socio-demographic factors on awareness, knowledge and perception was ascertained.

METHODS

A random sample of 120 potential participants over the age of 18 who attended the Oral Health Centre of Western Australia between 14 and 18 June 2010 were invited to participate in the survey. A total of 100 participants completed a face-to-face interview guided by a questionnaire.

RESULTS

Seventy-two per cent of the participants had heard of oral and pharyngeal carcinoma. Sixteen per cent knew that both smoking and drinking increased the risk of oral and pharyngeal carcinoma and 49% knew at least one sign or symptom of the cancer. Language spoken at home, education, and employment influenced cancer awareness and knowledge. Sixty-two per cent of the participants considered themselves not at risk of developing the cancer.

CONCLUSIONS

The findings suggest that knowledge concerning oral and pharyngeal carcinoma in the community may be limited and educational strategies may be required to improve such knowledge.

Abstract PD06-01: A Single Treatment with Targeted Intraoperative Radiotherapy (TARGIT) Is Similar to Several Weeks of External Beam Radiotherapy (EBRT) with Respect to Efficacy and Safety, and Has Obvious Advantages to the Patient and the Economy

Background: After breast-conserving surgery, 90% of local recurrences occur within the index quadrant despite the presence of multicentric cancers elsewhere in the breast. Thus, restriction of radiation therapy to the tumour bed during surgery might be adequate for selected patients. Materials and methods: Having safely piloted the new technique of single-dose targeted intraoperative radiotherapy (TARGIT) with Intrabeam, we launched the TARGIT-A trial on March 24, 2000. In this prospective, randomised, non-inferiority trial, women aged 45 years or older with invasive ductal breast carcinoma undergoing breast-conserving surgery were enrolled to compare TARGIT with whole breast external beam radiotherapy (EBRT). The primary outcome was local recurrence in the conserved breast with a predefined absolute non-inferiority margin of 2-5%. Analysis was by intention-to-treat.

Results: 1113 patients were randomly allocated to TARGIT and 1119 were allocated to EBRT. The Kaplan-Meier estimate of local recurrence in the conserved breast at 4 years was 1-20% (95% CI 0-53-2-71) in the TARGIT and 0-95% (0.39-2-31) in the EBRT group (difference between groups 0.25%, −1.04 to 1.54; p=0.41). The frequency of any complications and major toxicity (TARGIT 3.3% vs. EBRT 3.9% p=0·44) was similar. Radiotherapy toxicity was lower in the TARGIT group (0.5% vs. 2.1%, p=0.002). 14% of patients who received TARGIT also received EBRT as per the protocol, i.e., the remaining 86% patients could safely avoid 3-6 weeks of daily radiotherapy treatments and its obvious associated costs in economic and human terms.

Discussion: For selected patients with early breast cancer, a single-dose targeted intraoperative radiotherapy should be considered as an alternative to whole breast EBRT delivered over several weeks. It could save time, effort, and money for the patient and the healthcare system, which is particularly relevant in the present times of healthcare reform. NB the main trial results have been presented in ASCO 2010 and published in the Lancet Online First.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD06-01.

Safety and efficacy of targeted intraoperative radiotherapy (TARGIT) for early breast cancer: First report of a randomized controlled trial at 10-years maximum follow-up

LBA517

Background: After breast conserving surgery, 90% of local recurrences (LR) occur within the index quadrant. Hence, restricting the radiation therapy to the immediate area around the tumour bed after removal of the primary tumour may be adequate (Vaidya JS, et al. Br Cancer.1996;74:820-4)

Methods: Having safely piloted a new technique of partial breast irradiation (Vaidya JS, Baum M, Tobias JS et al Ann Oncol 2001;12:1075-80) we launched the TARGIT-A trial in March 2000 comparing TARGIT vs. standard whole breast external beam radiotherapy (EBRT) after breast conserving surgery in patients ≥45 years with invasive duct carcinoma. LR was the primary outcome measure (core protocol: www.thelancet.com/protocol-reviews/99PRT-47 ). Trial accrual from 31 international centers is complete (n=2232), with 80% power to detect a difference in relapse rate of 2.5% - the non-inferiority margin.

Results: Median age was 63 (IQR 57-69), median tumor size 13mm (IQR 9-18mm), lymph nodes 17%+ve. Median follow-up is 24.6 months (max 10 years). Wound breakdown or delayed healing were reported in 28 of the TARGIT group and 20 in the EBRT group (p=0.24). RTOG grade 3 toxicity (nil grade 4) was seen in 6 vs. 21 (p=0.004) respectively. Overall local toxicity was equivalent (34/1092 TARGIT v. 41/1096 EBRT, p=0.42). The Kaplan-Meier estimate of LR in the breast, was 0.31% (CI 0.08-1.26) for TARGIT versus 0.29% for EBRT (CI 0.07-1.16) at 24 months.

Conclusions: In the TARGIT group, the radiotherapy toxicity was significantly lower than in the EBRT group, while the increase in wound complications was not statistically significant. This analysis suggests that at a median follow-up of 24 months the local control with TARGIT is comparable to EBRT. Longer term follow-up is essential and accrual in similar studies is encouraged.

[Table: see text]

Morbidity outcomes of 78,577 hysterectomies for benign reasons over 23 years

OBJECTIVE

To investigate the association of the method of hysterectomy for benign reasons with morbidity outcomes in Western Australia after taking other demographic, social and health-related factors into account.

DESIGN

Population-based retrospective observational study.

SETTING

All hospitals in Western Australia where hysterectomies were performed from 1981 to 2003.

POPULATION

All women aged 20 years or older who underwent a hysterectomy for benign reasons.

METHOD

Logistic and zero-truncated negative binomial regression analysis of record-linked administrative health data.

MAIN OUTCOME MEASURES

Relative odds of experiencing complications during the hysterectomy admission or readmission and relative length of stay in hospital by type of hysterectomy.

RESULTS

There were 78,577 hysterectomies performed for benign reasons from 1981 to 2003. Procedure-related haemorrhage (2.4%) was the most commonly recorded complication, followed by genitourinary disorders (1.9%), infection (1.6%) and urinary tract infections (1.6%). Vaginal hysterectomy was associated with reduced odds of infection and haemorrhage compared with abdominal procedures during the hysterectomy admission. Readmission rates increased from 5.4% in 1981-84 to 7.2% in 2000-03 as average length of stay decreased by 53% over the same time period. Women who underwent laparoscopically assisted vaginal hysterectomies and vaginal hysterectomies had increased odds of readmission for haemorrhage and genitourinary disorders compared with abdominal hysterectomy. Young age, increasing number of co-morbid conditions and having a complication at hysterectomy admission were also associated with increased odds of readmission.

CONCLUSION

These findings identify women at risk of readmission following hysterectomy and highlight an opportunity to modify early discharge and patient follow-up practices to reduce this risk.

Acute decompression illness and serum s100beta levels: a prospective observational pilot study

BACKGROUND

S100beta, a calcium binding protein associated with astroglial cells and other tissues has been shown to be raised in the serum of patients with a number of neurological pathologies. As there are no published data on serum S100beta determinations in recreational divers affected by decompression illness (DCI) this pilot study determines whether S100beta is a possible biochemical marker of DCI worthy of further investigation.

METHODS

Venous blood samples were drawn from patients diagnosed with, and treated for acute DCI at a hyperbaric facility and analysed for serum S100beta concentration and Creatine Kinase (CK) activity. Samples were taken at initial presentation, and again following final treatment.

RESULTS

Twenty one patients were included in the study. Neither S100beta, nor CK levels were significantly raised above population normal limits.

CONCLUSION

S100beta is not a clinically useful serum marker of acute DCI.

Methods of determining the relationship of the mandibular canal and third molars: a survey of Australian oral and maxillofacial surgeons

BACKGROUND

Surgical extraction of third molars is one of the most common oral and maxillofacial surgical procedures performed and may have a number of associated complications. One of these complications is inferior alveolar nerve (IAN) dysaesthesia or impairment of sensory perception (including paraesthesia and/or anaesthesia). Previous studies assume that most clinicians use various combinations of nine radiologic criteria on panoramic radiographs as indicators of the relationship and, therefore, predictors of the risk of postoperative dysaesthesia. Our study assessed both the current radiologic modalities and assessment criteria used by Australian oral and maxillofacial surgeons when determining the proximity of mandibular canal to third molars.

METHODS

A survey of all surgeon members of the Australian and New Zealand Association of Oral and Maxillofacial Surgeons (ANZOMS) practising in Australia was undertaken.

RESULTS

Of the 105 questionnaires sent to surgeons, 72 responses (68 per cent) were returned. All surgeons reported using the panoramic radiograph but only 25 per cent considered it sufficiently accurate in determining the relationship between the mandibular canal (MC) and the third molar root, while 61 per cent of surgeons use CT for this purpose but the average frequency of use was very low (five per cent). This study also revealed that the nine radiologic criteria on a panoramic radiograph are used to varying extents by Australian surgeons. Nearly all surgeons use 'change in MC direction' and 'MC narrowing' to determine and close relationship. Thirty-one per cent used superimposition of the MC and the root of the third molar alone and 24 per cent used appearance of contact of the root with the MC alone in the absence of any other radiologic criteria to indicate close or intimate relationship.

CONCLUSION

Further research is required to determine the accuracy and observer agreement or reliability of using the nine panoramic characteristics, to determine this relationship and whether the presurgical determination of proximity and position (buccal or lingual) of the canal utilizing CT has any usefulness in determining the surgical protocol or affect on postoperative morbidity.

Incidence and risk factors for injury in non-elite Australian Football

This paper identifies the risk and protective factors for injury in non-elite Australian Football. Five hundred and thirty five non-elite Australian footballers completed a baseline questionnaire at the commencement of the 1997 preseason. Participants were telephoned each month during the 1997 and 1998 playing seasons to provide details of their exposure at training and games and any injury experiences in the previous four weeks. The incidence of injury in this study was 24 injuries per 1000 player hours. The risk factors for injury were identified as: not wearing sports-specific football boots (IRR 1.40, 95% CI 1.03-1.90); an existing back pathology (IRR 1.29, 95% CI 1.10-1.51); excessive foot pronation (IRR 1.29, 95% CI 1.07-1.56); and extroverted behaviour (IRR 1.01, 95% CI 1.00-1.03). Cooling down after training (IRR 0.95, 95% CI 0.90-0.99) and not being injured in the previous 12 months (IRR 0.73, 95% CI 0.61-0.88) were found to be protective against injury. This study found that there was a high risk of injury associated with playing Australian Football at a community level. Further research is required to gain an understanding of the mechanisms by which the identified risk factors influence injury risk in community level Australian Football.

Outcomes of myringoplasty in Australian Aboriginal children and factors associated with success: a prospective case series

The objective of this study was to assess the outcomes of myringoplasties in Aboriginal children and to identify factors associated with a successful outcome with the use of prospective case series from primary health care clinics and hospitals in four rural and remote regions of Western Australia. All 58 Aboriginal children, aged 5-15 years, who underwent 78 myringoplasties between 1 January 2000 and 30 June 2001 were included in the study. Complete postoperative (post-op) follow-up was achieved following 78% of myringoplasties. The main outcome measures were (a) success, i.e. an intact tympanic membrane and normal hearing six or more months post-op in the operated ear, (b) closure of the perforation, (c) Post-op hearing improvement. Forty-nine per cent of myringoplasties were successful, 72% resulted in closure or reduction in the size of the perforation and 51% resulted in hearing improvement. After controlling for age, sex, clustering and number of previous myringoplasties, no association was observed between success or hearing improvement and perforation size, or the presence of serous aural discharge at the time of surgery. Myringoplasty resulted in hearing improvement and/or perforation closure in a significant proportion of children. Thus, primary school-aged Aboriginal children in whom conservative management of chronic suppurative otitis media has been unsuccessful should have access to myringoplasty because of the positive impact on their socialization, language and learning that results from improved hearing.

Association of domestic exposure to volatile organic compounds with asthma in young children

AIM

To investigate the association between domestic exposure to volatile organic compounds (VOCs) and asthma in young children.

METHODS

A population based case-control study was conducted in Perth, Western Australia in children aged between 6 months and 3 years. Cases (n = 88) were children recruited at Princess Margaret Hospital accident and emergency department and discharged with asthma as the primary diagnosis; 104 controls consisted of children from the same age group without an asthma diagnosis identified through the Health Department of Western Australia. Information regarding the health status of the study children and characteristics of the home was collected using a standardised questionnaire. Exposure to VOCs, average temperature and relative humidity were measured in winter and summer in the living room of each participating household.

RESULTS

Cases were exposed to significantly higher VOC levels (microg/m3) than controls (p<0.01). Most of the individual VOCs appeared to be significant risk factors for asthma with the highest odds ratios for benzene followed by ethylbenzene and toluene. For every 10 unit increase in the concentration of toluene and benzene (microg/m3) the risk of having asthma increased by almost two and three times, respectively.

CONCLUSIONS

Domestic exposure to VOCs at levels below currently accepted recommendations may increase the risk of childhood asthma. Measurement of total VOCs may underestimate the risks associated with individual compounds.

Mortality and cancer incidence in a cohort of meatworkers

AIMS

To determine the risk of all cause mortality, cause specific mortality, and incident cancer in meatworkers.

METHODS

In a retrospective cohort study, a list of members of a meatworkers union in Australia was matched with the national death and cancer registries. Standardised mortality ratios (SMR) and standardised incidence ratios (SIR) were calculated using Australian population rates. Exposure to animal viruses, animal blood, animal faeces, and plastic pyrolysis products was assigned according to job title. A nested case control analysis examined the risk of mortality and cancer incidence by each exposure.

RESULTS

There were approximately 20 000 subjects available for analysis. Male workers had increased risk of mortality from all causes (SMR 116, 95% CI 105 to 128) and from injury (SMR 131, 95% CI 108 to 157). Risk of incident lung cancer in males was non-significantly increased (SIR 164, 95% CI 97 to 259) and males had a raised risk of head and neck cancer (SIR 188, 95% CI 103 to 315). There were no significant associations with specific exposures.

CONCLUSIONS

Compared to the general Australian population, meatworkers have increased risk of death from all causes, death from injury, and incident lung and head and neck cancer. Analysis by occupational exposures did not disclose any strong evidence of specific occupational risk factors, although this analysis was limited by small numbers of some outcomes and exposure assessment which was based on job titles only.

Subcutaneous glucose sensor values closely parallel blood glucose during insulin-induced hypoglycaemia

AIMS

To assess the accuracy of the Minimed continuous glucose monitoring system (CGMS) in estimating blood glucose concentration during a controlled reduction in blood glucose.

RESEARCH DESIGN AND METHODS

We studied nine adolescent diabetics (age 14 +/- 1.5 years) wearing the CGMS during hyperinsulinaemic hypoglycaemic clamp studies. The glucose values obtained by the CGMS were compared with the venous blood samples taken during the studies and measured at the bedside using a glucose oxidase technique.

RESULTS

Blood glucose was lowered from euglycaemia to a mean of 2.8 mmol/l over 120 min and maintained at that level for a further 40 min. A total of 429 paired glucose measurements were available for analysis. Analysis using weighted Deming regression and t-tests revealed small differences between the methods, with blood glucose levels slightly higher than interstitial fluid levels. The mean difference across all values was 0.13 mmol/l. The observed difference was greatest at blood glucose values < 3.3 mmol/l.

CONCLUSIONS

This study suggests that during a fall in systemic glucose the subcutaneous glucose sensor provides an accurate reflection of blood glucose. However, a small difference is apparent at blood glucose values < 3.3 mmol/l.

Preparing a new generation anaesthetic machine for patients susceptible to malignant hyperthermia

Anaesthetic machines are prepared for use with patients who are susceptible to malignant hyperpyrexia (MH) by flushing with oxygen at 10 l/min for ten minutes to reduce the anaesthetic concentration to 1 part per million (ppm) or less. Anaesthetic workstations are now often used in place of traditional machines. Workstations have greater internal complexity, and it is not known if they can be made safe for susceptible patients by flushing with oxygen. We used a high sensitivity infrared gas analyser to measure the washout of isoflurane from five Datex-Ohmeda workstations. Measurements were then repeated with a patient breathing circuit. Isoflurane washout occurred in an exponential manner. The time to reach a concentration of 1 ppm at the fresh gas outlet was 17 +/- 7 minutes, and all machines had reached less than 2 ppm by ten minutes. The washout of isoflurane from the machine and patient breathing circuit was much slower than from the machine alone, with a concentration less than 2 ppm reached only after 30 minutes. We conclude that the Datex-Ohmeda workstation can be prepared for use in MH susceptible patients by flushing with oxygen at 10 l/min for ten minutes. Flushing of the patient breathing system is not straightforward, and we recommend using a clean T-piece circuit. If the circle system and ventilator are required for anaesthesia, we suggest using new breathing hoses, rebreathing bag and soda lime cartridge, and ventilating an artificial lung for 30 minutes with a fresh gas flow rate of 10 l/min and tidal volume of 1 litre.