Mortality in systemic lupus erythematosus

OBJECTIVE

To examine mortality rates in the largest systemic lupus erythematosus (SLE) cohort ever assembled.

METHODS

Our sample was a multisite international SLE cohort (23 centers, 9,547 patients). Deaths were ascertained by vital statistics registry linkage. Standardized mortality ratio (SMR; ratio of deaths observed to deaths expected) estimates were calculated for all deaths and by cause. The effects of sex, age, SLE duration, race, and calendar-year periods were determined.

RESULTS

The overall SMR was 2.4 (95% confidence interval 2.3-2.5). Particularly high mortality was seen for circulatory disease, infections, renal disease, non-Hodgkin's lymphoma, and lung cancer. The highest SMR estimates were seen in patient groups characterized by female sex, younger age, SLE duration <1 year, or black/African American race. There was a dramatic decrease in total SMR estimates across calendar-year periods, which was demonstrable for specific causes including death due to infections and death due to renal disorders. However, the SMR due to circulatory diseases tended to increase slightly from the 1970s to the year 2001.

CONCLUSION

Our data from a very large multicenter international cohort emphasize what has been demonstrated previously in smaller samples. These results highlight the increased mortality rate in SLE patients compared with the general population, and they suggest particular risk associated with female sex, younger age, shorter SLE duration, and black/African American race. The risk for certain types of deaths, primarily related to lupus activity (such as renal disease), has decreased over time, while the risk for deaths due to circulatory disease does not appear to have diminished.

Outcomes of total hip and knee replacement: preoperative functional status predicts outcomes at six months after surgery

OBJECTIVE

To determine whether patients with knee or hip osteoarthritis (OA) who have worse physical function preoperatively achieve a postoperative status that is similar to that of patients with better preoperative function.

METHODS

This study surveyed an observational cohort of 379 consecutive patients with definite OA who were without other inflammatory joint diseases and were undergoing either total hip or knee replacement in a US (Boston) and a Canadian (Montreal) referral center. Questionnaires on health status (the Short Form 36 and Western Ontario and McMaster Universities Osteoarthritis Index) were administered preoperatively and at 3 and 6 months postoperatively. Physical function and pain due to OA were deemed the most significant outcomes to study.

RESULTS

Two hundred twenty-two patients returned their questionnaires. Patients in the 2 centers were comparable in age, sex, time to surgery, and proportion of hip/knee surgery. The Boston group had more education, lower comorbidity, and more cemented knee prostheses. Patients undergoing hip or knee replacement in Montreal had lower preoperative physical function and more pain than their Boston counterparts. In patients with lower preoperative physical function, function and pain were not improved postoperatively to the level achieved by those with higher preoperative function. This was most striking in patients undergoing total knee replacement.

CONCLUSION

Surgery performed later in the natural history of functional decline due to OA of the knee, and possibly of the hip, results in worse postoperative functional status.

Obesity and C-reactive protein in various populations: a systematic review and meta-analysis

Obesity has been associated with elevated levels of C-reactive protein (CRP), a marker of inflammation and predictor of cardiovascular risk. The objective of this systematic review and meta-analysis was to estimate the associations between obesity and CRP according to sex, ethnicity and age. MEDLINE and EMBASE databases were searched through October 2011. Data from 51 cross-sectional studies that used body mass index (BMI), waist circumference (WC) or waist-to-hip ratio (WHR) as measure of obesity were independently extracted by two reviewers and aggregated using random-effects models. The Pearson correlation (r) for BMI and ln(CRP) was 0.36 (95% confidence interval [CI], 0.30-0.42) in adults and 0.37 (CI, 0.31-0.43) in children. In adults, r for BMI and ln(CRP) was greater in women than men by 0.24 (CI, 0.09-0.37), and greater in North Americans/Europeans than Asians by 0.15 (CI, 0-0.28), on average. In North American/European children, the sex difference in r for BMI and ln(CRP) was 0.01 (CI, -0.08 to 0.06). Although limited to anthropometric measures, we found similar results when WC and WHR were used in the analyses. Obesity is associated with elevated levels of CRP and the association is stronger in women and North Americans/Europeans. The sex difference only emerges in adulthood.

Bayesian estimation of disease prevalence and the parameters of diagnostic tests in the absence of a gold standard

It is common in population screening surveys or in the investigation of new diagnostic tests to have results from one or more tests investigating the same condition or disease, none of which can be considered a gold standard. For example, two methods often used in population-based surveys for estimating the prevalence of a parasitic or other infection are stool examinations and serologic testing. However, it is known that results from stool examinations generally underestimate the prevalence, while serology generally results in overestimation. Using a Bayesian approach, simultaneous inferences about the population prevalence and the sensitivity, specificity, and positive and negative predictive values of each diagnostic test are possible. The methods presented here can be applied to each test separately or to two or more tests combined. Marginal posterior densities of all parameters are estimated using the Gibbs sampler. The techniques are applied to the estimation of the prevalence of Strongyloides infection and to the investigation of the diagnostic test properties of stool examinations and serologic testing, using data from a survey of all Cambodian refugees who arrived in Montreal, Canada, during an 8-month period.

Bayesian approaches to modeling the conditional dependence between multiple diagnostic tests

Many analyses of results from multiple diagnostic tests assume the tests are statistically independent conditional on the true disease status of the subject. This assumption may be violated in practice, especially in situations where none of the tests is a perfectly accurate gold standard. Classical inference for models accounting for the conditional dependence between tests requires that results from at least four different tests be used in order to obtain an identifiable solution, but it is not always feasible to have results from this many tests. We use a Bayesian approach to draw inferences about the disease prevalence and test properties while adjusting for the possibility of conditional dependence between tests, particularly when we have only two tests. We propose both fixed and random effects models. Since with fewer than four tests the problem is nonidentifiable, the posterior distributions are strongly dependent on the prior information about the test properties and the disease prevalence, even with large sample sizes. If the degree of correlation between the tests is known a priori with high precision, then our methods adjust for the dependence between the tests. Otherwise, our methods provide adjusted inferences that incorporate all of the uncertainty inherent in the problem, typically resulting in wider interval estimates. We illustrate our methods using data from a study on the prevalence of Strongyloides infection among Cambodian refugees to Canada.

Beta-blockers in congestive heart failure. A Bayesian meta-analysis

PURPOSE

Congestive heart failure is an important cause of patient morbidity and mortality. Although several randomized clinical trials have compared beta-blockers with placebo for treatment of congestive heart failure, a meta-analysis quantifying the effect on mortality and morbidity has not been performed recently.

DATA SOURCES

The MEDLINE, Cochrane, and Web of Science electronic databases were searched from 1966 to July 2000. References were also identified from bibliographies of pertinent articles.

STUDY SELECTION

All randomized clinical trials of beta-blockers versus placebo in chronic stable congestive heart failure were included.

DATA EXTRACTION

A specified protocol was followed to extract data on patient characteristics, beta-blocker used, overall mortality, hospitalizations for congestive heart failure, and study quality.

DATA SYNTHESIS

A hierarchical random-effects model was used to synthesize the results. A total of 22 trials involving 10 135 patients were identified. There were 624 deaths among 4862 patients randomly assigned to placebo and 444 deaths among 5273 patients assigned to beta-blocker therapy. In these groups, 754 and 540 patients, respectively, required hospitalization for congestive heart failure. The probability that beta-blocker therapy reduced total mortality and hospitalizations for congestive heart failure was almost 100%. The best estimates of these advantages are 3.8 lives saved and 4 fewer hospitalizations per 100 patients treated in the first year after therapy. The probability that these benefits are clinically significant (>2 lives saved or >2 fewer hospitalizations per 100 patients treated) is 99%. Both selective and nonselective agents produced these salutary effects. The results are robust to any reasonable publication bias.

CONCLUSIONS

beta-Blocker therapy is associated with clinically meaningful reductions in mortality and morbidity in patients with stable congestive heart failure and should be routinely offered to all patients similar to those included in trials.

Birth of a biome: insights into the assembly and maintenance of the Australian arid zone biota

The integration of phylogenetics, phylogeography and palaeoenvironmental studies is providing major insights into the historical forces that have shaped the Earth's biomes. Yet our present view is biased towards arctic and temperate/tropical forest regions, with very little focus on the extensive arid regions of the planet. The Australian arid zone is one of the largest desert landform systems in the world, with a unique, diverse and relatively well-studied biota. With foci on palaeoenvironmental and molecular data, we here review what is known about the assembly and maintenance of this biome in the context of its physical history, and in comparison with other mesic biomes. Aridification of Australia began in the Mid-Miocene, around 15 million years, but fully arid landforms in central Australia appeared much later, around 1-4 million years. Dated molecular phylogenies of diverse taxa show the deepest divergences of arid-adapted taxa from the Mid-Miocene, consistent with the onset of desiccation. There is evidence of arid-adapted taxa evolving from mesic-adapted ancestors, and also of speciation within the arid zone. There is no evidence for an increase in speciation rate during the Pleistocene, and most arid-zone species lineages date to the Pliocene or earlier. The last 0.8 million years have seen major fluctuations of the arid zone, with large areas covered by mobile sand dunes during glacial maxima. Some large, vagile taxa show patterns of recent expansion and migration throughout the arid zone, in parallel with the ice sheet-imposed range shifts in Northern Hemisphere taxa. Yet other taxa show high lineage diversity and strong phylogeographical structure, indicating persistence in multiple localised refugia over several glacial maxima. Similar to the Northern Hemisphere, Pleistocene range shifts have produced suture zones, creating the opportunity for diversification and speciation through hybridisation, polyploidy and parthenogenesis. This review highlights the opportunities that development of arid conditions provides for rapid and diverse evolutionary radiations, and re-enforces the emerging view that Pleistocene environmental change can have diverse impacts on genetic structure and diversity in different biomes. There is a clear need for more detailed and targeted phylogeographical studies of Australia's arid biota and we suggest a framework and a set of a priori hypotheses by which to proceed.

Removal of heavy metals from water sources in the developing world using low-cost materials: A review

Heavy metal contamination is a growing concern in the developing world. Inadequate water and wastewater treatment, coupled with increased industrial activity, have led to increased heavy metal contamination in rivers, lakes, and other water sources in developing countries. However, common methods for removing heavy metals from water sources, including membrane filtration, activated carbon adsorption, and electrocoagulation, are not feasible for developing countries. As a result, a significant amount of research has been conducted on low-cost adsorbents to evaluate their ability to remove heavy metals. In this review article, we summarize the current state of research on the removal of heavy metals with an emphasis on low-cost adsorbents that are feasible in the context of the developing world. This review evaluates the use of adsorbents from four major categories: agricultural waste; naturally-occurring soil and mineral deposits; aquatic and terrestrial biomass; and other locally-available waste materials. Along with a summary of the use of these adsorbents in the removal of heavy metals, this article provides a summary of the influence of various water-quality parameters on heavy metals and these adsorbents. The proposed adsorption mechanisms for heavy metal removal are also discussed.

The psychological burden of peanut allergy as perceived by adults with peanut allergy and the parents of peanut-allergic children

BACKGROUND

Peanut-allergic patients are affected by a condition which forces them and their families to exercise extreme dietary vigilance and experience constant uncertainty throughout their lives.

OBJECTIVE

To compare the quality of life and family relations of children and adults with a peanut allergy to that of children and adults with a rheumatological disease.

METHODS

Patients with a confirmed diagnosis of peanut allergy or a rheumatological disease completed (for children less than 18 years, by proxy) self-report questionnaires regarding the impact of their condition on their quality of life and family relations. A vertical visual analogue scale and the Impact on Family Questionnaire (IFQ) served as outcome measures.

RESULTS

One hundred and fifty-three peanut-allergic children were compared with 69 children with a rheumatological disease while 37 peanut-allergic adults were compared with 42 adults with a rheumatological disease. The parents of peanut-allergic children, compared to the parents of children with a rheumatological disease, reported that their children had significantly more disruption in their daily activities. Furthermore, the parents of peanut-allergic children reported more impairment in the familial-social dimension of the IFQ. Conversely, adults with a chronic rheumatological disease reported more disruption in their family relations than peanut-allergic adults.

CONCLUSION

Given the considerable disruption in daily activities and family relations reported by the parents of peanut-allergic children, accurate diagnosis of peanut allergy is essential. Our work should make health care professionals dealing with children with confirmed peanut allergy more aware of the support that these families may require. Furthermore, we hope to motivate food industries to offer more 'peanut free' products to decrease the dietary restrictions of these patients while minimizing their potential for accidental ingestion.

Spatial relationships in early signaling events of flow-mediated endothelial mechanotransduction

Blood flow interactions with the vascular endothelium represent a specialized example of mechanical regulation of cell function that has important physiological and pathological cardiovascular consequences. The endothelial monolayer in vivo acts as a signal transduction interface for forces associated with flowing blood (hemodynamic forces) in the acute regulation of artery tone and chronic structural remodeling of arteries, including the pathology of atherosclerosis. Mechanisms related to spatial relationships at the cell surfaces and throughout the cell that influence flow-mediated endothelial mechanotransduction are discussed. In particular, flow-mediated ion channel activation and cytoskeletal dynamics are considered in relation to topographic analyses of the luminal and abluminal surfaces of living endothelial cells.

An international cohort study of cancer in systemic lupus erythematosus

OBJECTIVE

There is increasing evidence in support of an association between systemic lupus erythematosus (SLE) and malignancy, but in earlier studies the association could not be quantified precisely. The present study was undertaken to ascertain the incidence of cancer in SLE patients, compared with that in the general population.

METHODS

We assembled a multisite (23 centers) international cohort of patients diagnosed as having SLE. Patients at each center were linked to regional tumor registries to determine cancer occurrence. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers. Cancers expected were determined by multiplying person-years in the cohort by the geographically matched age, sex, and calendar year-specific cancer rates, and summing over all person-years.

RESULTS

The 9,547 patients from 23 centers were observed for a total of 76,948 patient-years, with an average followup of 8 years. Within the observation interval, 431 cancers occurred. The data confirmed an increased risk of cancer among patients with SLE. For all cancers combined, the SIR estimate was 1.15 (95% confidence interval [95% CI] 1.05-1.27), for all hematologic malignancies, it was 2.75 (95% CI 2.13-3.49), and for non-Hodgkin's lymphoma, it was 3.64 (95% CI 2.63-4.93). The data also suggested an increased risk of lung cancer (SIR 1.37; 95% CI 1.05-1.76), and hepatobiliary cancer (SIR 2.60; 95% CI 1.25, 4.78).

CONCLUSION

These results support the notion of an association between SLE and cancer and more precisely define the risk of non-Hodgkin's lymphoma in SLE. It is not yet known whether this association is mediated by genetic factors or exogenous exposures.

Estimation of the prevalence of low bone density in Canadian women and men using a population-specific DXA reference standard: the Canadian Multicentre Osteoporosis Study (CaMos)

The Canadian Multicentre Osteoporosis Study (CaMos) is a prospective cohort study which will measure the incidence and prevalence of osteoporosis and fractures, and the effect of putative risk factors, in a random sample of 10,061 women and men aged > or = 25 years recruited in approximately equal numbers in nine centers across Canada. In this paper we report the results of studies to establish peak bone mass (PBM) which would be appropriate reference data for use in Canada. These reference data are used to estimate the prevalence of osteoporosis and osteopenia in Canadian women and men aged > or = 50 years. Participants were recruited via randomly selected household telephone listings. Bone mineral density (BMD) of the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry using Hologic QDR 1000 or 2000 or Lunar DPX densitometers. BMD results for lumbar spine and femoral neck were converted to a Hologic base. BMD of the lumbar spine in 578 women and 467 men was constant to age 39 years giving a PBM of 1.042 +/- 0.121 g/cm2 for women and 1.058 +/- 0.127 g/cm2 for men. BMD at the femoral neck declined from age 29 years. The mean femoral neck BMD between 25 and 29 years was taken as PBM and was found to be 0.857 +/- 0.125 g/cm2 for women and 0.910 +/- 0.125 g/cm2 for men. Prevalence of osteoporosis, as defined by WHO criteria, in Canadian women aged > or = 50 years was 12.1% at the lumbar spine and 7.9% at the femoral neck with a combined prevalence of 15.8%. In men it was 2.9% at the lumbar spine and 4.8% at the femoral neck with a combined prevalence of 6.6%.

A long-term study of hydroxychloroquine withdrawal on exacerbations in systemic lupus erythematosus. The Canadian Hydroxychloroquine Study Group

The ability of antimalarials to moderate severe disease activity in systemic lupus erythematosus (SLE) is plausible but undemonstrated. We evaluated the long-term effectiveness of maintaining treatment with hydroxychloroquine sulphate (HCQ) to prevent major flares in quiescent SLE. Forty-seven patients with quiescent SLE who had been randomized to take HCQ (n = 25) or placebo (n = 22) as part of a 24-week withdrawal trial were evaluated for an additional 3 years. The primary outcome was time to a major flare of SLE which resulted in either the institution of or an increase in the current dosage of prednisone of 10 mg/day or more, or institution of therapy with immunosuppressive agents. Secondary outcomes included the specific subtype of these major flares (glomerulonephritis, vasculitis or other) and hospitalization for an exacerbation of SLE. An intent-to-treat analysis was conducted. Over the 42 months of study, 11 of 22 (50%) patients randomized initially to placebo, and seven of 25 (28%) patients randomized to continue treatment experienced a major flare. The relative risk of major flare for those randomized to continue HCQ compared with controls was 0.43 (95% CI: 0.17, 1.12). The relative risks for subtypes of flares were 0.26 (95% CI: 0.03, 2.54) for nephritis, 0.51 (95% CI: 0.09, 3.08) for vasculitis and 0.65 (95% CI: 0.17, 2.41) for flares characterized by other symptoms. The relative risk of hospitalization for major flare for patients randomized to continue hydroxychloroquine was 0.58 (95% CI: 0.13, 2.60). While the results are not statistically significant, they are compatible with the clinical belief that HCQ has a long-term protective effect against major disease flares in SLE and suggest that on average, HCQ use reduces major flares by 57% (95% CI: 83% reduction to 12% increase).

The influence of osteoporotic fractures on health-related quality of life in community-dwelling men and women across Canada

Health-related quality of life (HRQL) was examined in relation to prevalent fractures in 4816 community-dwelling Canadian men and women 50 years and older participating in the Canadian Multicentre Osteoporosis Study (CaMos). Fractures were of three categories: clinically recognized main fractures, subclinical vertebral fractures and fractures at other sites. Main fractures were divided and analyzed at the hip, spine, wrist/forearm, pelvis and rib sites. Baseline assessments of anthropometric data, medical history, therapeutic drug use, spinal radiographs and prevalent fractures were obtained from all participants. The SF-36 instrument was used as a tool to measure HRQL. A total of 652 (13.5%) main fractures were reported. Results indicated that hip, spine, wrist/forearm, pelvis and rib fractures had occurred in 78 (1.6%), 40 (0.8%), 390 (8.1%), 19 (0.4%) and 125 (2.6%) individuals, respectively (subjects may have had more than one main fracture). Subjects who had experienced a main prevalent fracture had lower HRQL scores compared with non-fractured participants. The largest differences were observed in the physical functioning (-4.0; 95% confidence intervals (CI): -6.0, -2.0) and role-physical functioning domains (-5.8; 95% CI: -9.5, -2.2). In women, the physical functioning domain was most influenced by hip (-14.9%; 95% CI: -20.9, -9.0) and pelvis (-18.1; 95% CI: -27.6, -8.6) fractures. In men, the role-physical domain was most affected by hip fractures (-35.7; 95% CI: -60.4, -11.1). Subjects who experienced subclinical vertebral fractures had lower HRQL scores than those without prevalent fractures. In conclusion, HRQL was lower in the physical functioning domain in women and the role-physical domain in men who sustained main fractures at the hip. Subclinical vertebral fractures exerted a moderate effect on HRQL.

Estimating the sensitivity and specificity of Kato-Katz stool examination technique for detection of hookworms, Ascaris lumbricoides and Trichuris trichiura infections in humans in the absence of a 'gold standard'

The accuracy of the Kato-Katz technique in identifying individuals with soil-transmitted helminth (STH) infections is limited by day-to-day variation in helminth egg excretion, confusion with other parasites and the laboratory technicians' experience. We aimed to estimate the sensitivity and specificity of the Kato-Katz technique to detect infection with Ascaris lumbricoides, hookworm and Trichuris trichiura using a Bayesian approach in the absence of a 'gold standard'. Data were obtained from a longitudinal study conducted between January 2004 and December 2005 in Samar Province, the Philippines. Each participant provided between one and three stool samples over consecutive days. Stool samples were examined using the Kato-Katz technique and reported as positive or negative for STHs. In the presence of measurement error, the true status of each individual is considered as latent data. Using a Bayesian method, we calculated marginal posterior densities of sensitivity and specificity parameters from the product of the likelihood function of observed and latent data. A uniform prior distribution was used (beta distribution: alpha=1, beta=1). A total of 5624 individuals provided at least one stool sample. One, two and three stool samples were provided by 1582, 1893 and 2149 individuals, respectively. All STHs showed variation in test results from day to day. Sensitivity estimates of the Kato-Katz technique for one stool sample were 96.9% (95% Bayesian Credible Interval [BCI]: 96.1%, 97.6%), 65.2% (60.0%, 69.8%) and 91.4% (90.5%, 92.3%), for A. lumbricoides, hookworm and T. trichiura, respectively. Specificity estimates for one stool sample were 96.1% (95.5%, 96.7%), 93.8% (92.4%, 95.4%) and 94.4% (93.2%, 95.5%), for A. lumbricoides, hookworm and T. trichiura, respectively. Our results show that the Kato-Katz technique can perform with reasonable accuracy with one day's stool collection for A. lumbricoides and T. trichiura. Low sensitivity of the Kato-Katz for detection of hookworm infection may be related to rapid degeneration of delicate hookworm eggs with time.

Factors determining conversion to laparotomy in patients undergoing laparoscopic cholecystectomy

Laparoscopic cholecystectomy (LC) has been performed increasingly in an outpatient setting. Conversion from LC to open cholecystectomy (OC) is sometimes required. To predict conversion to OC, a single institutional study of 1,676 consecutive patients in whom LC was attempted was performed. Factors evaluated were age, sex, history of acute cholecystitis, pancreatitis, or jaundice, previous abdominal surgery, abnormalities of liver function tests, thickened gallbladder wall identified by preoperative ultrasound, obesity or morbid obesity, and cumulative institutional experience in LC. Conversion to OC was required in 90 of 1,676 (5.4%) patients. Significant preoperative predictors of conversion were acute cholecystitis, increasing age, male sex, obesity, and thickened gallbladder wall found by ultrasound. Nonobese women younger than age 65 years with symptoms of biliary colic and normal gallbladder wall thickness found by preoperative ultrasound required conversion only 1.9% of the time. These predictors may be useful in planning a program of ambulatory or short stay surgical units for patients undergoing LC and for comparing data between series.

Molecular support for vicariance as a source of diversity in rainforest

The origin of high diversity in tropical rainforests is attributed to divergence amongst relatively mesic, late Pleistocene refuges. To test this hypothesis we analysed sequence variation within the mitochondrial DNA of populations of six rainforest-dwelling vertebrate species (one lizard and five birds) in the Wet Tropical rainforests of northeastern Australia. Vicariance among historical refuges was indicated by geographically congruent variation across a historical climatic barrier previously predicted by modelling. Sequence divergence across the barrier varied widely, being highest in species with lowest vagility and greatest restriction to rainforest. A high altitude, rainforest-restricted species was exceptional in lacking mtDNA variation. These data support the suggested role of vicariance in promoting evolutionary diversity in rainforests but also indicate variation in the timing of vicariance events, with most speciation or divergence events occurring well before the late Pleistocene. The relation between the amount of molecular divergence and current ecology suggests a sequence of isolation events, perhaps of increasing severity, occurring between the late Tertiary and the late Pleistocene.

A controlled study of diffuse idiopathic skeletal hyperostosis. Clinical features and functional status

Diffuse idiopathic skeletal hyperostosis (DISH) is a common but little-studied disorder in the elderly that is infrequently recognized by physicians. Its prevalence in adults over 40 years of age is estimated at 3.8% for men and 2.6% for women. The present case-control study evaluated the history of pain and stiffness, radicular pain and enthesitis, physical findings on the musculoskeletal examination, and level of physical and psychologic disability in 130 persons: 56 patients with DISH, 43 control patients with spondylosis of the lumbar spine, and 31 healthy control patients. DISH patients were more likely to report a past history of upper extremity pain, medial epicondylitis of the elbow, enthesitis of the patella or heel, or dysphagia than spondylosis patients. They had more extremity and spinal stiffness and pain than healthy controls. DISH patients weighed more at a young age and their body mass index was greater at the time of the clinical evaluation than either spondylosis or healthy control patients. On musculoskeletal examination, DISH patients had a greater reduction in neck rotation and thoracic movements than either spondylosis patients or healthy controls, and had a greater reduction in lumbar movement than healthy controls. DISH patients had similar levels of spinal disability and physical disability overall, as measured by standardized indices, as spondylosis patients. No differences were found among the 3 groups of patients for the laboratory tests evaluated. DISH is clearly a distinct disorder with signs and symptoms that distinguish it from other causes of spinal complaint and from healthy individuals. It has the potential to cause major disability. Future studies need to address the natural history of DISH, pursue pathogenic mechanisms, and evaluate treatment modalities.

Do doctors accurately assess coronary risk in their patients? Preliminary results of the coronary health assessment study

OBJECTIVE

To evaluate the ability of doctors in primary care to assess risk patients' risk of coronary heart disease.

DESIGN

Questionnaire survey.

SETTING

Continuing medical education meetings, Ontario and Quebec, Canada.

SUBJECTS

Community based doctors who agreed to enroll in the coronary health assessment study.

MAIN OUTCOME MEASURE

Ratings of coronary risk factors and estimates by doctors of relative and absolute coronary risk of two hypothetical patients and the "average" 40 year old Canadian man and 70 year old Canadian woman.

RESULTS

253 doctors answered the questionnaire. For 30 year olds the doctors rated cigarette smoking as the most important risk factor and raised serum triglyceride concentrations as the least important; for 70 year old patients they rated diabetes as the most important risk factor and raised serum triglyceride concentrations as the least important. They rated each individual risk factor as significantly less important for 70 year olds than for 30 year olds (all risk factors, P < 0.001). They showed a strong understanding of the relative importance of specific risk factors, and most were confident in their ability to estimate coronary risk. While doctors accurately estimated the relative risk of a specific patient (compared with the average adult) they systematically overestimated the absolute baseline risk of developing coronary disease and the risk reductions associated with specific interventions.

CONCLUSIONS

Despite guidelines on targeting patients at high risk of coronary disease accurate assessment of coronary risk remains difficult for many doctors. Additional strategies must be developed to help doctors to assess better their patients' coronary risk.

Laboratory tests as predictors of disease exacerbations in systemic lupus erythematosus. Why some tests fail

OBJECTIVE

To evaluate whether changes in laboratory test values are either simultaneous with or precede disease exacerbations in patients with systemic lupus erythematosus (SLE).

METHODS

At 9, 6, and 3 months preceding a flare in disease activity (defined as a rise of > or = 6 points in the modified SLE Disease Activity Index), laboratory tests were performed to measure patients' hematocrit levels, white blood cell, lymphocyte, and platelet counts, erythrocyte sedimentation rate, C1q binding, DNA binding, and levels of C3 and C4. Flares were classified as either present or absent, and were divided into renal, vasculitic, central nervous system, skin, serosal, and musculoskeletal subgroups. The predictive patterns were 1) the simultaneous change in the test value from the mean of 9, 6, and 3 months preceding a flare to the time of the flare; 2) the gradual change, following a linear time trend, in test results for the same time points; and 3) the change from the mean of 9 and 6 months to 3 months preceding a flare, as a measure of predictive ability. These analyses used repeated-measures analysis of variance models. Multiple linear regression was used to study the cross-sectional association of average-over-time differences in test results with patients' flare subgroup.

RESULTS

Among 202 patients with SLE (median followup 86.5 months), 83 flares occurred in 53 patients. Of 189 statistical contrasts performed, only 14 were significant (versus 10 expected), and the differences were of minor importance. Nonetheless, evaluation of all test results over each patient's observed disease course revealed significant differences between selected test values in association with specific types of flare.

CONCLUSION

Fluctuations in laboratory test values are poor predictors of disease exacerbations in SLE. Cross-sectional evaluation of some test results revealed differences at the time of flare for those patients who were destined to have different types of flares, because these values differed over the entire study period. This pattern explains the frequent cross-sectional association of disease activity with laboratory test results, and the inconsistent association of flares with recent changes in test values.

Changes in power with resistance training in older and younger men and women

BACKGROUND

Muscle power diminishes with increasing age and inactivity. The capacity for older adults to increase muscle power with resistance exercise has not been examined; therefore, we examined the influence of progressive resistance training (PRT) on muscle power output in 17 men and women aged 56-66 years, and compared their responses to 15 men and women aged 21-30 years.

METHODS

All subjects performed 12 weeks of PRT at a workload equivalent to 80% of the one repetition maximum (1RM). All training and assessments of 1RM and power were made on Keiser pneumatic resistance machines. Subjects performed five exercises, three sets per exercise, twice weekly. Muscle power was measured (isotonically) at resistances equivalent to 40, 60, and 80% of the 1RM, on the knee extension and arm pull machines.

RESULTS

All subjects increased arm pull power similarly at 40 and 60% of 1RM, independent of age or sex. There was not a significant increase in arm pull power at 80% of 1RM. Older and younger subjects also had similar absolute increases in leg extensor power at 40 and 60% of 1RM, but men responded with greater absolute gains than women at these percentages (p < .05). The increase in leg extensor power at 80% of 1RM was similar in all groups. Older and younger subjects increased strength similarly in all exercises except the left knee extension. Independent of age, men increased strength more than women in all exercises except the double leg press.

CONCLUSIONS

These data demonstrate that individuals in their sixth decade can still improve muscle power (and strength); however, men may realize greater absolute gains than women.

Evaluation of decision rules for referring women for bone densitometry by dual-energy x-ray absorptiometry

CONTEXT

Identification of women with low bone mineral density (BMD) is an important strategy in reducing the incidence of osteoporotic fractures. However, screening all women is not recommended.

OBJECTIVES

To assess the diagnostic properties of 4 decision rules--Simple Calculated Osteoporosis Risk Estimation (SCORE), Osteoporosis Risk Assessment Instrument (ORAI), Age, Body Size, No Estrogen (ABONE), and body weight less than 70 kg (weight criterion)--for selecting women for dual-energy x-ray absorptiometry (DXA) testing and to compare results with recommendations made in the National Osteoporosis Foundation (NOF) practice guidelines.

DESIGN AND SETTING

Analysis of data from the Canadian Multicentre Osteoporosis Study, a population-based community sample, collected from 9 study centers across Canada between February 1996 and September 1997.

PARTICIPANTS

Postmenopausal women aged 45 years or older (N = 2365) without bone disease who had DXA data for the femoral neck, data to apply selection criteria, and who were not currently taking estrogens or who had been taking hormone replacement therapy for 5 or more years.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and area under the receiver operating characteristic (AUROC) curve of each of the 4 decision rules and the NOF guidelines for identifying women with a BMD T score of less than -1.0 SD, less than -2.0 SD, and no more than -2.5 SD at the femoral neck, and percentages of women recommended for testing, stratified by BMD level and age.

RESULTS

The percent of women with a BMD T score less than -1, less than -2, and no more than -2.5 were 68.3%, 25.4%, and 10.0%, respectively. The AUROC curves were greatest using SCORE and ORAI. The sensitivity for identifying women with a BMD T score of less than -2.0 was 93.7% (95% confidence interval [CI], 91.8%-95.6%) using the NOF guidelines and was 97.5% (95% CI, 96.3%-98.8%), 94.2% (95% CI, 92.3%-96.1%), 79.1% (95% CI, 75.9%-82.3%), and 79.6% (95% CI, 76.4%-82.8%), respectively, using the SCORE, ORAI, ABONE, and weight criterion. However, the NOF guidelines also resulted in 74.4% (95% CI, 71.3%-77.6%) of women with a normal BMD (T score of -1.0 or higher) being tested compared with 69.2% (95% CI, 65.9%-72.5%), 56.3% (95% CI, 52.7%-59.8%), 35.8% (95% CI, 32.4%-39.2%), and 38.1% (95% CI, 34.6%-41.6%), respectively, using the 4 decision rules. Assessments suggest that ABONE and weight criterion are not useful case-finding approaches.

CONCLUSION

The SCORE and ORAI decision rules are better than the NOF guidelines at targeting BMD testing in high-risk patients. The acceptability of these rules in clinical practice merits further investigation given their potential effect on the use of densitometry services.

Associations among disease conditions, bone mineral density, and prevalent vertebral deformities in men and women 50 years of age and older: cross-sectional results from the Canadian Multicentre Osteoporosis Study

This cross-sectional cohort study of 5566 women and 2187 men 50 years of age and older in the population-based Canadian Multicentre Osteoporosis Study was conducted to determine whether reported past diseases are associated with bone mineral density or prevalent vertebral deformities. We examined 12 self-reported disease conditions including diabetes mellitus (types 1 or 2), nephrolithiasis, hypertension, heart attack, rheumatoid arthritis, thyroid disease, breast cancer, inflammatory bowel disease, neuromuscular disease, Paget's disease, and chronic obstructive pulmonary disease. Multivariate linear and logistic regression analyses were performed to determine whether there were associations among these disease conditions and bone mineral density of the lumbar spine, femoral neck, and trochanter, as well as prevalent vertebral deformities. Bone mineral density measurements were higher in women and men with type 2 diabetes compared with those without after appropriate adjustments. The differences were most notable at the lumbar spine (+0.053 g/cm2), femoral neck (+0.028 g/cm2), and trochanter (+0.025 g/cm2) in women, and at the femoral neck (+0.025 g/cm2) in men. Hypertension was also associated with higher bone mineral density measurements for both women and men. The differences were most pronounced at the lumbar spine (+0.022 g/cm2) and femoral neck (+0.007 g/cm2) in women and at the lumbar spine (+0.028 g/cm2) in men. Although results were statistically inconclusive, men reporting versus not reporting past nephrolithiasis appeared to have clinically relevant lower bone mineral density values. Bone mineral density differences were -0.022, -0.015, and -0.016 g/cm2 at the lumbar spine, femoral neck, and trochanter, respectively. Disease conditions were not strongly associated with vertebral deformities. In summary, these cross-sectional population-based data show that type 2 diabetes and hypertension are associated with higher bone mineral density in women and men, and nephrolithiasis may be associated with lower bone mineral density in men. The importance of these associations for osteoporosis case finding and management require further and prospective studies.

The association between osteoporotic fractures and health-related quality of life as measured by the Health Utilities Index in the Canadian Multicentre Osteoporosis Study (CaMos)

Osteoporotic fractures can be a major cause of morbidity. It is important to determine the impact of fractures on health-related quality of life (HRQL). A total of 3,394 women and 1,122 men 50 years of age and older, who were recruited for the Canadian Multicentre Osteoporosis Study (CaMos), participated in this cross-sectional study. Minimal trauma fractures of the hip, pelvis, spine, lower body (included upper and lower leg, knee, ankle, and foot), upper body (included arm, elbow, sternum, shoulder, and clavicle), wrist and hand (included forearm, hand, and finger), and ribs were studied. Participants with subclinical vertebral deformities were also examined. The Health Utilities Index Mark II and III Systems were used to assess HRQL. Past osteoporotic fractures varied in prevalence from 1.2% (pelvis) to 27.8% (lower body) in women and 0.3% (pelvis) to 29.3% (wrist) in men. Multivariate linear regression analyses [parameter estimates and corresponding 95% confidence intervals (CI)] indicated that minimal trauma fractures were negatively associated with HRQL and that this relationship depends on fracture type and gender. The multi-attribute scores for the Mark II system were negatively related to hip (-0.05; 95% CI: -0.09, -0.01), lower body (-0.02; 95% CI: -0.03, -0.000), and subclinical vertebral fractures (-0.02; 95% CI: -0.03, -0.00) for women. The multi-attribute scores for the Mark III system were negatively related to hip (-0.09; 95% CI: -0.14, -0.03) and rib fractures (-0.06; 95% CI: -0.11, -0.00) for women, and rib fractures (-0.06; 95% CI: -0.12, -0.00) for men. In conclusion, this study demonstrates a negative association between osteoporotic fractures and quality of life in both women and men.

The relationship between cancer and medication exposures in systemic lupus erythaematosus: a case-cohort study

OBJECTIVE

To examine if, in systemic lupus erythaematosus (SLE), exposure to immunosuppressive therapy (cyclophosphamide, azathioprine, methotrexate) increases cancer risk.

METHODS

A case-cohort study was performed within a multi-site international SLE cohort; subjects were linked to regional tumour registries to determine cancer cases occurring after entry into the cohort. We calculated the hazard ratio (HR) for cancer after exposure to an immunosuppressive drug, in models that controlled for other medications (anti-malarial drugs, systemic glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs), aspirin), smoking, age, sex, race/ethnicity, geographic location, calendar year, SLE duration, and lupus damage scores. In the primary analyses, exposures were treated categorically (ever/never) and as time-dependent.

RESULTS

Results are presented from 246 cancer cases and 538 controls without cancer. The adjusted HR for overall cancer risk after any immunosuppressive drug was 0.82 (95% CI 0.50-1.36). Age > or = 65, and the presence of non-malignancy damage were associated with overall cancer risk. For lung cancer (n = 35 cases), smoking was also a prominent risk factor. When looking at haematological cancers specifically (n = 46 cases), there was a suggestion of an increased risk after immunosuppressive drug exposures, particularly when these were lagged by a period of 5 years (adjusted HR 2.29, 95% CI 1.02-5.15).

CONCLUSIONS

In our SLE sample, age > or = 65, damage, and tobacco exposure were associated with cancer risk. Though immunosuppressive therapy may not be the principal driving factor for overall cancer risk, it may contribute to an increased risk of haematological malignancies. Future studies are in progress to evaluate independent influence of medication exposures and disease activity on risk of malignancy.