Longitudinal research: methods for maximizing subject follow-up

Early intervention for hazardous alcohol use has been shown repeatedly to be effective in reducing alcohol consumption, limiting alcohol-related problems and improving biochemical parameters. However, in most studies the follow-up period has been 2 years or less. The current paper presents progress on a 10-year follow-up of a randomized controlled trial of early intervention. Methods used for tracing subjects and ensuring minimal refusals are detailed. The intensity of effort required to locate subjects is documented and recommendations for ensuring good follow-up rates are made. At completion of follow-up, 72.5% of the sample reviewed here and 78.2% of the total cohort had been traced. Our experiences demonstrate that long-term follow-up is feasible, given sufficient planning and persistence.

Regarding "Edema and leg volume: Methods of assessment" (Letters to the Editor)

I noted with interest the article by Drs Perrin and Guex, entitled &dquo;Edema and leg volume: Methods of assessment,&dquo; published in Angiology 51:9-12, 2000. This was a timely and comprehensive review of the various methods in clinical use for the assessment of peripheral edema, notably in the leg. I would like to take this opportunity to alert readers to a further technique useful for this purpose, namely, bioelectrical impedance analysis. An early reportl described its use for the measurement of edema in the leg, but other than its successful use for the assessment of edema in the arm following masteCtoMy,2,1 the potential of the method remains to be fully realized. This is unfortunate since the method directly and quantifiably measures edema.

Methods for effective fluidization of particulate food materials

Depending on the size and shape of the materials, methods employed to achieve effective fluidization during fluid bed drying varies from use of simple hole distributors for small, light weight materials to special techniques for lager and/or moist materials. This paper reviews common air distributors used in fluidized bed drying of food particulates. Also it reviews special methods of fluidizing larger irregular food particulates.

Absolute risk of breast cancer for Australian women with a family history

Background: The purpose of the present paper was to estimate the absolute risk of breast cancer over the remainder of a lifetime in Australian women with different categories of family history. Methods: Age-specific breast cancer incidence rates were adjusted for screening effects, and rates in those with no family history were estimated using the attributable fraction (AF). Relative risks from a published meta-analysis were applied to obtain incidence rates for different categories of family history, and age-specific incidence was converted to cumulative risk of breast cancer. The risk estimates were based upon Australian population statistics and published relative risks. Breast cancer incidence was from New South Wales women for 1996. The AF was calculated using prevalence of a family history of breast cancer from data on Queensland women. The cumulative absolute risk of breast cancer was calculated from decade and mid-decade ages to age 79 years, not adjusted for competing causes of death. Results: Lifetime risk is approximately 8.6% (1 in 12) for the general population and 7.8% (1 in 13) for those without a family history. Women with one relative affected have lifetime risks of 1 in 6-8 and those with two relatives affected have lifetime risks of 1 in 4-6. The cumulative residual lifetime risk decreases with advancing age; by age 60 years all groups with only one relative affected have well above a 90% probability of not developing breast cancer to age 79 years. Conclusions: These Australian risk statistics are useful for public information and in the clinical setting. Risks given here apply to women with average breast cancer risk from other risk factors.

Initial results of ultrasound screening for aneurysm of the abdominal aorta in Western Australia: relevance for endoluminal treatment of aneurysm disease

Background. Increased life expectancy in men during the last thirty years is largely due to the decrease in mortality from cardiovascular disease in the age group 29-69 yr. This change has resulted in a change in the disease profile of the population with conditions such as aneurysm of the abdominal aorta (AAA) becoming more prevalent. The advent of endoluminal treatment for AAA has encouraged prophylactic intervention and fuelled the argument to screen for the disease. The feasibility of inserting an endoluminal graft is dependent on the morphology and growth characteristics of the aneurysm. This study used data from a randomized controlled trial of ultrasound screening for AAA in men aged 65-83 yr in Western Australia for the purpose of determining the norms of the living anatomy in the pressurized infrarenal aorta. Aims. To examine (1) the diameters of the infra-renal aorta in aneurysmal and non-aneurysmal cases, (2) the implications for treatment modalities, with particular reference to endoluminal grafting, which is most dependent on normal and aneurysmal morphology, and (3) any evidence to support the notion that northern Europeans are predisposed to aneurysmal disease. Methods. Using ultrasound, a randomized control trial was established in Western Australia to assess the value of a screening program in males aged 65-83 yr, The infra-renal aorta was defined as aneurysmal if the maximum diameter was 30 mm or more. Aortic diameter was modelled both as a continuous tin mm) and as a binary outcome variable, for those men who had an infra-renal diameter of 30 mm or more. ANOVA and linear regression were used for modelling aortic diameter as a continuum, while chi-square analysis and logistic regression were used in comparing men with and without the diagnosis of AAA. Findings. By December 1998, of 19.583 men had been invited to undergo ultrasound screening for AAA, 12.203 accepted the invitation (corrected response fraction 70.8%). The prevalence of AAA increased with age from 4.8% at 65 yr to 10.8% at 80 yr (chi (2) = 77.9, df = 3, P<0.001). The median (IQR) diameter for the non-aneurysmal group was 21.4 mm (3.3 mm) and there was an increase (<chi>(2) = 76.0, df = 1, P<0.001) in the diameter of the infra-renal aorta with age. Since 27 mm is the 95th centile for the non-aneurysmal infra-renal aorta, a diameter of 30 mm or more is justified as defining an aneurysm. The risk of AAA was higher in men of Australian (OR = 1.0) and northern European origin (OR = 1.0, 95%CL: 0.9. 1.2) compared with those of Mediterranean origin (OR = 0.5, 99%CL: 0.4, 0.7). Conclusion. Although screening has not yet been shown to reduce mortality from AAA. these population-based data assist the understanding of aneurysmal disease and the further development and use of endoluminal grafts for this condition. (C) 2001 Published by Elsevier Science Ltd on behalf of The International Society for Cardiovascular Surgery.

Expression of RANTES and CCR1 in oral lichen planus and association with mast cell migration

Background: T lymphocytes and mast cells infiltrate the lamina propria in oral lichen planus (OLP). Chemokines and their receptors are involved in T cell and mast cell migration and accumulation during the inflammatory process. Methods: In the present study, we investigated the role of RANTES and its receptors in OLP using immunohistochemistry, RT-PCR and an in vitro chemotaxis assay. Results: RANTES and CCR1 were expressed on T cells and mast cells in OLP, while OLP lesional T cell supernatants stimulated CCR1 mRNA expression in a human leukemia mast cell line (HMC-1). TNF-alpha stimulated CCR1, CCR4 and CCR5 mRNA expression in the same cell line. OLP lesional T cell supernatants stimulated HMC-1 migration, which was partly inhibited by anti-RANTES antibody. Conclusions: The present study shows, for the first time, the distribution of RANTES and CCR1 in OLR It is hypothesized that RANTES and CCR1 may play important roles in mast cell trafficking and related events in OLP.

Methods for prediction of peptide binding to MHC molecules: A comparative study

Background: A variety of methods for prediction of peptide binding to major histocompatibility complex (MHC) have been proposed. These methods are based on binding motifs, binding matrices, hidden Markov models (HMM), or artificial neural networks (ANN). There has been little prior work on the comparative analysis of these methods. Materials and Methods: We performed a comparison of the performance of six methods applied to the prediction of two human MHC class I molecules, including binding matrices and motifs, ANNs, and HMMs. Results: The selection of the optimal prediction method depends on the amount of available data (the number of peptides of known binding affinity to the MHC molecule of interest), the biases in the data set and the intended purpose of the prediction (screening of a single protein versus mass screening). When little or no peptide data are available, binding motifs are the most useful alternative to random guessing or use of a complete overlapping set of peptides for selection of candidate binders. As the number of known peptide binders increases, binding matrices and HMM become more useful predictors. ANN and HMM are the predictive methods of choice for MHC alleles with more than 100 known binding peptides. Conclusion: The ability of bioinformatic methods to reliably predict MHC binding peptides, and thereby potential T-cell epitopes, has major implications for clinical immunology, particularly in the area of vaccine design.

Undergraduate student experience in dental service delivery in rural South Australia: An analysis of costs and benefits

Background, Rural experience for dental students can provide valuable clinical education, change attitudes to rural practice, and make a valuable contribution to clinical service provision. The aim of this paper is to assess the costs and benefits of service delivery by students through rural training programmes Methods: Groups of two students worked in the public dental clinics in adjacent rural centres where there had been long-term difficulties in recruiting staff. The costs and benefits of the programme were assessed by the impact on waiting lists, the total cost per patient of, a course of care and by the marginal cost of adding service provision by students to existing arrangements. Results: The total costs of emergency and complete treatment provided by students were greater than the costs of treatment provided by public-sector dentists but less than the costs of private providers treating public patients. However, the value of services were greater when care was provided by students or private providers and the marginal cost of students providing services was 50-70 per cent of the cost of care provided by public dentists. Conclusion: This assessment suggests that the service benefits achieved compliment the primary objective of influencing the attitude of students to rural practice.

Is there a role for axillary dissection for patients with operable breast cancer in this era of conservatism?

Background: The trend in breast cancer surgery is toward more conservative operative procedures. The new staging technique of sentinel node biopsy facilitates the identification of pathological node-negative patients in whom axillary dissection may be avoided. However, patients with a positive sentinel node biopsy would require a thorough examination of their nodal status. An axillary dissection provides good local control, and accurate staging and prognostic information to inform decisions about adjuvant therapy. In addition, the survival benefit of axillary treatment is still debated. The objectives of the present study were to examine the pattern of lymph node metastases in the axilla, and evaluate the merits of a level III axillary dissection. Methods : Between June 1997 and May 2000, 308 patients underwent a total of 320 level III dissections as part of their treatment for operable invasive breast cancer. The three axillary levels were marked intraoperatively, and the contents in each level were submitted and examined separately. The patterns of axillary lymph node (ALN) metastases were examined, and factors associated with 4 positive nodes, and level III ALN metastases were evaluated by univariate and multivariate analyses. Results: An average of 25 lymph nodes were examined per case (range: 8-54), and using strict anatomical criteria, the mean numbers of ALN found in levels I, II and III were 18 (range: 2-43), 4 (range: 0 19), and 3 ( range: 0-11), respectively. Axillary lymph node involvement was found in 45% of the cases (143/320). Of the 143 cases, 78% (n = 111) had involvement of level I nodes only, and 21% (n = 30) had positive ALN in levels II and, or, III, in addition to level I. Involvement of lymph nodes in level II or III without a level I metastasis was found in two cases only (0.6%). By including level II, in addition to level I, in the dissection, four cases (1%) were converted from one to three positive nodes to 4 positive nodes (P = 0.64). By the inclusion of level III to a level I and II dissection, three cases (1%) were converted from one to three positive nodes to 4 positive nodes (P = 0.74). Involvement of lymph nodes in level III was found in 22 cases (7%), and 51 cases (16%) had 4 positive nodes. Palpability of ALN, pathological tumour size, and lymphovascular invasion (LVI), were significantly associated with level III involvement and 4 positive nodes by univariate and multivariate analyses. The frequencies of level III involvement and 4 positive nodes in patients with palpable ALN were 22% and 42%, respectively. The corresponding frequencies in patients with a clinically negative axilla, and a primary tumour which was >20 mm and LVI positive, were over 14% and 31%, respectively. Conclusion: Level III axillary dissection is appropriate for patients with palpable ALN, and in those with a tumour which is >20 mm and LVI positive, principally to reduce the risk of axillary recurrence. Staging accuracy is achieved with a level II dissection, or even a level I dissection alone based on strict anatomical criteria. Sentinel node biopsy is a promising technique in identifying pathological node-positive patients in whom an axillary clearance provides optimal local control and staging information.

Perioperative epidural analgesia and outcome after major abdominal surgery in high-risk patients

In a primary analysis of a large recently completed randomized trial in 915 high-risk patients undergoing major abdominal surgery, we found no difference in outcome between patients receiving perioperative epidural analgesia and those receiving IV opioids, apart from the incidence of respiratory failure. Therefore, we performed a selected number of predetermined subgroup analyses to identify specific types of patients who may have derived benefit from epidural analgesia. We found no difference in outcome between epidural and control groups in subgroups at increased risk of respiratory or cardiac complications or undergoing aortic surgery, nor in a subgroup with failed epidural block (all P > 0.05). There was a small reduction in the duration of postoperative ventilation (geometric mean [SD]: control group, 0.3 [6.5] h, versus epidural group, 0.2 [4.8] h, P = 0.048). No differences were found in length of stay in intensive care or in the hospital. There was no relationship between frequency of use of epidural analgesia in routine practice outside the trial and benefit from epidural analgesia in the trial. We found no evidence that perioperative epidural analgesia significantly influences major morbidity or mortality after major abdominal surgery.

Is there an association between chronic lung disease and abdominal aortic aneurysm expansion?

Background: Although there is evidence demonstrating an association between chronic obstructive pulmonary disease (COPD) and abdominal aortic aneurysm (AAA), it is not clear whether COPD predicts greater rates of expansion of established aneurysms. We sought such an association in a cohort of men with aneurysms detected in a population-based study of screening for aneurysms. Methods: In addition to regular aortic ultrasound scans, 179 men with AAA underwent full lung function testing in order to identify the presence of COPD and its subgroups, emphysema and other obstructive ventilatory defects (OVD). The rate of expansion of each aneurysm was calculated and the men were divided into 'rapid expanders' (3 mm or more per year) and 'slow expanders' (less than 3 mm per year). Any association with the presence of COPD or smoking was tested using a multivariate model. Results: Over a median follow-up period of 36 months the mean rate of aortic expansion for the cohort of 179 men was 2.1 mm/year. There was no significant difference in prevalence of COPD (68% overall) or having ever been a smoker (87% overall) between the rapid expanders and the slow expanders. Conclusions: Although there was a high prevalence of COPD among men with an AAA, there was no association between the rate of expansion of AAA and the presence of any form of this disease.

Predicting energy requirements in the clinical setting: Are current methods evidence based?

Estimating energy requirements is necessary in clinical practice when indirect calorimetry is impractical. This paper systematically reviews current methods for estimating energy requirements. Conclusions include: there is discrepancy between the characteristics of populations upon which predictive equations are based and current populations; tools are not well understood, and patient care can be compromised by inappropriate application of the tools. Data comparing tools and methods are presented and issues for practitioners are discussed. (C) 2003 International Life Sciences Institute.