Long-term survivor mixture model with random effects: application to a multi-centre clinical trial of carcinoma

A mixture model incorporating long-term survivors has been adopted in the field of biostatistics where some individuals may never experience the failure event under study. The surviving fractions may be considered as cured. In most applications, the survival times are assumed to be independent. However, when the survival data are obtained from a multi-centre clinical trial, it is conceived that the environ mental conditions and facilities shared within clinic affects the proportion cured as well as the failure risk for the uncured individuals. It necessitates a long-term survivor mixture model with random effects. In this paper, the long-term survivor mixture model is extended for the analysis of multivariate failure time data using the generalized linear mixed model (GLMM) approach. The proposed model is applied to analyse a numerical data set from a multi-centre clinical trial of carcinoma as an illustration. Some simulation experiments are performed to assess the applicability of the model based on the average biases of the estimates formed. Copyright (C) 2001 John Wiley & Sons, Ltd.

Randomized controlled trial of two cigarette quit programmes in coronary care patients after acute myocardial infarction

Background: Tobacco cessation after acute myocardial infarction (AMI) substantially improves outcome but how effective individual programmes are needs to be established. To date, few studies have examined this factor. Aims: To assess the outcome of two smoking cessation programmes after AMI. Methods: One hundred and ninety-eight current smokers admitted to coronary care with an AMI participated in a randomized controlled study comparing two outpatient tobacco interventions, the Stanford Heart Attack Staying Free (SF) programme and a Usual Care (UC) programme. Results: Log-rank analyses revealed that patients in the SF programme were retained longer (P < 0.001) and had higher cotinine validated abstinence rates (P < 0.001) compared with patients in the UC programme. Twelve months after intervention, 39% of the SF programme compared with 2% of the UC programme demonstrated cotinine validated tobacco cessation, representing a significant reduced relapse rate in the SF programme (chi (2), P < 0.001). Conclusions: The SF smoking cessation programme initiated in hospital can significantly reduce smoking rates at 12 months after myocardial infarction. Although superior to the UC quit programme, Australian outcomes were lower than the American programme originators' published outcomes.

A cost-minimization analysis of the societal costs of realtime teledermatology compared with conventional care: results from a randomized controlled trial in New Zealand

A randomized controlled trial was carried out to measure the societal costs of realtime teledermatology compared with those of conventional hospital care in New Zealand. Two rural health centres were linked to a specialist hospital via ISDN at 128 kbit/s. Over 10 months, 203 patients were referred for a specialist dermatological consultation and 26 were followed up, giving a total of 229 consultations. Fifty-four per cent were randomized to the teledermatology consultation and 46% to the conventional hospital consultation. A cost-minimization analysis was used to calculate the total costs of both types of dermatological consultation. The total cost of the 123 teledermatology consultations was NZ$34,346 and the total cost of the 106 conventional hospital consultations was NZ$30,081. The average societal cost of the teledermatology consultation was therefore NZ$279.23 compared with NZ$283.79 for the conventional hospital consultation. The marginal cost of seeing an additional patient was NZ$135 via teledermatology and NZ$284 via conventional hospital appointment. From a societal viewpoint, and assuming an equal outcome, teledermatology was a more cost-efficient use of resources than conventional hospital care.

A randomized controlled trial assessing the health economics of realtime teledermatology compared with conventional care: an urban versus rural perspective

A randomized controlled trial was carried out to measure the cost-effectiveness of realtime teledermatology compared with conventional outpatient dermatology care for patients from urban and rural areas. One urban and one rural health centre were linked to a regional hospital in Northern Ireland by ISDN at 128 kbit/s. Over two years, 274 patients required a hospital outpatient dermatology referral -126 patients (46%) were randomized to a telemedicine consultation and 148 (54%) to a conventional hospital outpatient consultation. Of those seen by telemedicine, 61% were registered with an urban practice, compared with 71% of those seen conventionally. The clinical outcomes of the two types of consultation were similar - almost half the patients were managed after a single consultation with the dermatologist. The observed marginal cost per patient of the initial realtime teledermatology consultation was f52.85 for those in urban areas and f59.93 per patient for those from rural areas. The observed marginal cost of the initial conventional consultation was f47.13 for urban patients and f48.77 for rural patients. The total observed costs of teledermatology were higher than the costs of conventional care in both urban and rural areas, mainly because of the fixed equipment costs. Sensitivity analysis using a real-world scenario showed that in urban areas the average costs of the telemedicine and conventional consultations were about equal, while in rural areas the average cost of the telemedicine consultation was less than that of the conventional consultation.

Randomised controlled trial of telemedicine for new neurological outpatient referrals

Objective-To test the hypothesis that telemedicine for new patient referrals to neurological outpatients is as efficient and acceptable as conventional face to face consultation. Methods-A randomised controlled trial between two groups: face to face (FF) and telemedicine (TM). This study was carried out between a neurological centre and outlying clinics at two distant hospitals linked by identical medium cost commercial interactive video conferencing equipment with ISDN lines transmitting information at 384 kbits/s. The same two neurologists carried out both arms of the study. Of the 168 patients who were suitable for the study, 86 were randomised into the telemedicine group and 82 into the face to face group. Outcome measures were (I) consultation process: (a) number of investigations; (b) number of drugs prescribed; (c) number of patient reviews and (2) patient satisfaction: (a) confidence in consultation; (b) technical aspects of consultation; (c) aspects surrounding confidentiality. Diagnostic categories were also measured to check equivalence between the groups: these were structural neurological, structural non-neurological, nonstructural, and uncertain. Results-Diagnostic categories were similar (p>0.5) between the two groups. Patients in the telemedicine group had significantly more investigations (p=0.001). There was no difference in the number of drugs prescribed (p>0.5). Patients were generally satisfied with both types of consultation process except for concerns about confidentiality and embarrassment in the telemedicine group (p=0.017 and p=0.005 respectively). Conclusion-Telemedicine for new neurological outpatients is possible and feasible but generates more investigations and is less well accepted than face to face examination.

Guilty? An explanation of the Lockerbie trial. (Case notes)

The Lockerbie Trial, concerning the explosion of Pan Am flight 103 over Lockerbie, Scotland, in 1988, took place in the Netherlands because of the fear that pre-trial publicity would make a fair trial impossible and also fears for the physical safety of the accused - case for the prosecution - application of Scottish law - report of an observer at the trial, Professor Kochler - the International Criminal Court - leave to appeal granted.

Surgical outcomes of a randomized prospective trial involving patients with a proximal femoral fracture

Background: An orthopaedic management/patient-focused care unit (OMPFCU) involving a dedicated orthopaedic-geriatrics liaison team was established at the Royal Brisbane Hospital in 1994 in an effort to safely accelerate rehabilitation of patients with proximal femoral fractures. Methods: The surgical outcomes of the patients were monitored in order to determine whether accelerated rehabilitation had any significant adverse effects on the surgical outcomes, measured by mortality, readmission to hospital, deep wound infection, fracture union delay, mobility and the revision surgery rate. Results: No significant difference was recorded in mortality and morbidity, deep wound infection and revision surgery rates between patients in the Royal Brisbane Hospital OMPFCU and those in standard care in the orthopaedic surgery wards. Conclusion: Accelerated rehabilitation for patients with a proximal femoral fracture in a major teaching hospital can be accomplished safely.

Breaking the deadlock over an Australian trial of injectable opioid maintenance

INJECTABLE HEROIN MAINTENANCE has been advocated as a form of treatment for opioid dependence that would attract, and retain in treatment, addicts who have either not sought treatment or who have failed at other forms of treatment, including methadone maintenance. Advocates of heroin maintenance argue that it would increase the proportion of addicts in treatment and reduce heroin use, drug related crime, and deaths due to overdose.

Controlled partial mine ventiliation recirculation trial at Mount Isa Mines

The ventilation and cooling of deep, hot mines present particular problems in Australia as a consequence of the surface climate, the size of the underground voids, the degree of mechanization and the cost of power in remote areas. A preliminary investigation of the effects of controlled partial recirculation of air was conducted in Mount Isa Mines' Deep Copper section. Gas and dust concentrations were measured in the exhaust air of the major working section to assess the potential for recirculating exhaust air to the intake airways to reduce the cost of providing an acceptable working environment in the deep parts of the mine. Studies were undertaken of airborne dust deposition in vertical airways and the efficiency of usage of the ventilation air in diluting contaminants. It was established that 45% of the respirable dust was deposited in a 130-m vertical raise and 60% of the air supplied to the section could be reused or recirculated. The first major field trial of a controlled partial recirculation system in Australia was undertaken in the light of these results and demonstrated excellent potential for significant reduction in ventilation costs. Gas and dust contaminant levels were well below the threshold limit values during the trial. It is concluded that controlled partial recirculation can be a practical, effective and safe aid to normal ventilation practice in Australian deep, hot mines.

A field trial of the effect of improved piglet management on smallholder sow productivity in the Philippines

We conducted a randomised, controlled field trial during 1998/1999 to evaluate the hypothesis that improved piglet management would improve the reproductive performance of smallholder sows. Simple changes were introduced into the treatment herds including the construction of a heated piglet-separation pen, vitamin injections, creep feeding and early weaning. The control herds were unchanged. Data were collected from all sows in each enrolled herd over two farrowings. We enrolled 176 sows, including 170 (96 treatment and 74 control) sows that remained throughout the study period. Significant differences in the reproductive performance of treatment and control sows were recorded for interfarrowing interval (median 176 versus 220 days), average number liveborn over 2 litters (11 versus 12), and average preweaning mortality over 2 litters (0 versus 37%). Based on a discount rate of 17%, the benefit-cost ratio of the treatment was 11.1 and 12.1 over 3 and 5 years, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.

Early toxicity from preoperative radiotherapy with continuous infusion 5-fluorouracil for resectable adenocarcinoma of the rectum: A phase II trial for the Trans-Tasman Radiation Oncology Group

Purpose: To assess the toxicity and the efficacy of preoperative radiotherapy with continuous infusion 5-fluorouracil (5-FU) for locally advanced adenocarcinoma of the rectum. Methods and Materials: Eligible patients had newly diagnosed localized adenocarcinoma of the rectum within 12 cm of the anal verge, Stage T3-4, and were suitable for curative resection. Eighty-two patients were treated with radiotherapy-50.4 Gy in 28 fractions in 5.6 weeks, given concurrently with continuous infusion 5-FU, using either 96-h/week infusion at 300 mg/m(2)/day or 7-days/week infusion at 225 mg/m(2)/day. Results: The median age was 59 years (range, 27-87), and 67% of patients were male. Pretreatment stages of the rectal cancer were T3, 89% and resectable T4, 11%, with endorectal ultrasound confirmation in 67% of patients. Grade 3 acute toxicity occurred in 5 of 82 patients (6%; 95% confidence interval [CI], 2-14%). Types of surgical resection were anterior resection, 61%; abdominoperineal resection, 35%; and other procedures, 4%. There was no operative mortality. Anastomotic leakage after low anterior resection occurred in 3 of 50 patients (6%; 95% CI, 1-17%). The pathologic complete response rate was 16% (95% CI, 9-26%). Pathologic Stages T2 or less occurred in 51%. Conclusion: Preoperative radiotherapy with continuous infusion 5-FU for locally advanced rectal cancer is a safe regimen, with a significant downstaging effect. It does not seem to lead to a significant increase in serious surgical complications. (C) 2001 Elsevier Science Inc.