Illustrating risk: anaphylaxis through the eyes of the food-allergic child

The risk perception research is widely focused on children as targets of risk. To date, very few studies have consulted with the impacted group to assess the perceptions of risk associated with the exposures of interest. Much less research has investigated the experiences of children at risk for anaphylaxis, their concerns, and the psychosocial stresses associated with risk. The present study explores the perceptions and experiences of Ontario students with anaphylaxis, and their parents regarding school as a safe place in order to inform school policy around risk management and coping. A "child-centered" analytical framework incorporating illustrative techniques within interpretative analysis is outlined. Five prominent themes: (a) social and environmental barriers to safety, (b) coping strategies, (c) emotional burden of responsibility, (d) balance of responsibility (transitions), and (e) redefining "normal" are discussed. Results found that "child-centered" techniques empowered children in a process that is meaningful and relevant to their lives. A preliminary framework for understanding what risk means to children highlighted the differences in how they cope in the public sphere of school.

Healthcare cost and loss of productivity in a Canadian population of patients with and without lupus nephritis

OBJECTIVE

To compare the healthcare cost and loss of productivity in patients with systemic lupus erythematosus (SLE) with (LN) and without lupus nephritis (lupus nephritis-negative, LNN).

METHOD

Patients were classified into those with active (ALN and ALNN) and inactive disease (ILN and ILNN). Patients reported on visits to healthcare professionals and use of diagnostic tests, medications, assistive devices, alternative treatments, hospital emergency visits, surgical procedures, and hospitalizations as well as loss of productivity in the 4 weeks preceding enrollment.

RESULTS

Enrollment was 141 patients, 79 with LN and 62 LNN. Patients with LN were more likely to visit rheumatologists and nephrologists, undergo diagnostic tests, and had higher costs for medications than patients who were LNN. The annual healthcare cost averaged $CAN 12,597 ± 9946 for patients with LN and $10,585 ± 13,149 for patients who were LNN, a difference of $2012 (95% CI -$2075, $6100). Patients with ALN had more diagnostic tests and surgical procedures, contributing to a significantly higher annual direct cost ($14,224 ± 10,265) compared to patients with ILN ($9142 ± 8419) and a difference of $5082 (95% CI $591, $9573). The healthcare cost was not different between patients with ALNN and patients with ILNN. In patients with LN and patients who were LNN, < 50% were employed and on average missed 6.5-9 days of work per month. The loss of productivity was significantly higher for caregivers of patients with LN than caregivers of patients who were LNN.

CONCLUSION

Healthcare cost and loss of productivity were similar between patients with LN and patients who were LNN; the loss of productivity for caregivers is higher for patients with LN; and the healthcare cost is greater in ALN than in ILN.

Medication use in systemic lupus erythematosus

OBJECTIVE

To evaluate factors affecting therapeutic approaches used in clinical practice for the management of systemic lupus erythematosus (SLE), in a multicenter cohort.

METHODS

We combined data from 10 clinical adult SLE cohort registries in Canada. We used multivariate generalized estimating equation methods to model dichotomized outcomes, running separate regressions where the outcome was current exposure of the patient to specific medications. Potential predictors of medication use included demographic (baseline age, sex, residence, race/ethnicity) and clinical factors (disease duration, time-dependent damage index scores, and adjusted mean SLE Disease Activity Index-2K scores). The models also adjusted for clustering by center.

RESULTS

Higher disease activity and damage scores were each independent predictors of exposure to nonsteroid immunosuppressive agents, and for exposure to prednisone. This was not definitely demonstrated for antimalarial agents. Older age at diagnosis was independently and inversely associated with exposure to any of the agents studied (immunosuppressive agents, prednisone, and antimalarial agents). An additional independent predictor of prednisone exposure was black race/ethnicity (adjusted RR 1.46, 95% CI 1.18, 1.81). For immunosuppressive exposure, an additional independent predictor was race/ethnicity, with greater exposure among Asians (RR 1.39, 95% CI 1.02, 1.89) and persons identifying themselves as First Nations/Inuit (2.09, 95% CI 1.43, 3.04) than among whites. All of these findings were reproduced when adjustment for disease activity was limited to renal involvement.

CONCLUSION

Ours is the first portrayal of determinants of clinical practice patterns in SLE, and offers interesting real-world insights. Further work, including efforts to determine how differing clinical approaches may influence outcome, is in progress.

Anti-TNF therapy and pregnancy outcomes in women with inflammatory arthritis

Women suffering from inflammatory arthritis may experience a change in disease activity during and after pregnancy. Although the majority will improve, some women may need to continue therapy throughout pregnancy and/or in the lactation period. Since certain disease-modifying antirheumatic drugs have proven to be human teratogens, treatment is limited in these women. Anti-TNF agents fall within the US FDA category B concerning fetal risk, indicating that no adequate and well-controlled studies have been conducted in pregnant or lactating women. However, in the last decade, numerous case series and case reports of pregnancies exposed to anti-TNF therapy have accumulated in the literature. Since these agents may constitute an important therapeutic alternative in pregnant women facing persistent or increased disease activity, we propose a review of the available information on the safety of anti-TNF agents in pregnancy and lactation.

Role of food labels in accidental exposures in food-allergic individuals in Canada

BACKGROUND

Little is known about the impact of food labeling on the allergic consumer.

OBJECTIVE

To determine the proportion of food-allergic individuals attributing an accidental exposure to inappropriate labeling, failure to read a food label, or ignoring a precautionary statement and to identify factors associated with accidental exposures.

METHODS

Food-allergic individuals or their caregivers were recruited from a Canadian registry of individuals with a physician-confirmed diagnosis of peanut allergy and from allergy awareness organizations. Participants completed questionnaires regarding accidental exposures due to specific food labeling issues. The association between accidental exposures and characteristics of food-allergic individuals or their caregivers was estimated using multivariate logistic regression models.

RESULTS

Of 1,862 potential participants, 1,454 (78.1%) responded. Of the 47.8% (95% confidence interval [CI], 45.1%-50.5%) of respondents who experienced an accidental exposure, 47.0% (95% CI, 43.1%-50.9%) attributed the event to inappropriate labeling, 28.6% (95% CI, 25.1%-32.2%) to failure to read a food label, and 8.3% (95% CI, 6.3%-10.7%) to ignoring a precautionary statement. Food-allergic individuals who were allergic to peanut, tree nut, fish, or shellfish were less likely to experience an accidental exposure due to the allergen not being identified in plain language.

CONCLUSIONS

A considerable proportion of accidental exposures are attributed to inappropriate labeling, failure to read labels, and ignoring precautionary statements. Clear and consistent labeling of food allergens combined with increased consumer education is necessary to improve consumer confidence and compliance and to reduce accidental exposures.

Polymyalgia rheumatica prevalence in a population-based sample

OBJECTIVE

To determine polymyalgia rheumatica (PMR) prevalence using population-based administrative data, and to estimate the error associated with case ascertainment approaches when using these databases.

METHODS

Cases were ascertained using physician billing and hospitalization data from the province of Manitoba (population 1.1 million). Focusing on the population age >/=45 years, we compared 3 different case definition algorithms and also used statistical methods that accounted for imperfect case ascertainment to estimate the prevalence and the properties of the ascertainment algorithms. A hierarchical Bayesian latent class regression model was developed that also allowed us to assess differences across patient demographics (sex and region of residence).

RESULTS

Using methods that account for the imperfect nature of both billing and hospitalization databases, we estimated the prevalence of PMR in women age >/=45 years to be lower in urban areas (754.5 cases/100,000; 95% credible interval [95% CrI] 674.1-850.3) compared with rural areas (1,004 cases/100,000; 95% CrI 886.3-1,143). This regional trend was also seen in men age >/=45 years, where the prevalence was estimated at 273.6 cases/100,000 (95% CrI 219.8-347.6) in urban areas and 380.7 cases/100,000 (95% CrI 311.3-468.1) in rural areas. Billing data appeared more sensitive in ascertaining cases than hospitalization data, and a large proportion of diagnoses was made by physicians other than rheumatologists.

CONCLUSION

These data suggest a higher prevalence of PMR in rural versus urban regions. Our approach demonstrates the usefulness of methods that adjust for the imperfect nature of multiple information sources, which also allow for estimation of the sensitivity of different case ascertainment approaches.

Malignancy in systemic lupus erythematosus: what have we learned?

What have we learnt about cancer risk in systemic lupus erythematosus (SLE) over the past decade? One important lesson is that data do confirm a slightly increased risk in SLE for all cancers combined, compared to that in the general population. However, it is clear that this is largely driven by an increased risk for haematological malignancies, particularly non-Hodgkin's lymphoma (NHL), although Hodgkin's lymphoma may be increased as well. In addition, there is evidence for a moderately increased risk of lung cancer, and possibly for rarer cancer types such as hepatobiliary and vulvar/vaginal malignancies. Unfortunately, the most clinically relevant question--the mechanism underlying the association between cancer and SLE--remains largely unanswered. Key issues remaining relate to the links between cancer risk, SLE disease activity, and medication exposures. Much of the recent data suggest that disease-related factors may be at least as important as medication exposures for certain cancers, such as NHL. The independent effects of drug exposures versus disease activity in mediating cancer risk in SLE remain unknown. Work is in progress to further elucidate these important issues. Meanwhile, there is good evidence that cervical dysplasia is increased in women with SLE. This may be mediated by decreased clearance of the human papilloma virus, which some suggest is an innate characteristic of SLE patients. However, an increased risk of cervical dysplasia is also associated with immunosuppressive medication exposures, particularly cyclophosphamide. For these reasons, it is important that women with SLE follow established guidelines for cervical cancer screening.

Scleroderma prevalence: demographic variations in a population-based sample

OBJECTIVE

To estimate the prevalence of systemic sclerosis (SSc) using population-based administrative data, and to assess the sensitivity of case ascertainment approaches.

METHODS

We ascertained SSc cases from Quebec physician billing and hospitalization databases (covering approximately 7.5 million individuals). Three case definition algorithms were compared, and statistical methods accounting for imperfect case ascertainment were used to estimate SSc prevalence and case ascertainment sensitivity. A hierarchical Bayesian latent class regression model that accounted for possible between-test dependence conditional on disease status estimated the effect of patient characteristics on SSc prevalence and the sensitivity of the 3 ascertainment algorithms.

RESULTS

Accounting for error inherent in both the billing and the hospitalization data, we estimated SSc prevalence in 2003 at 74.4 cases per 100,000 women (95% credible interval [95% CrI] 69.3-79.7) and 13.3 cases per 100,000 men (95% CrI 11.1-16.1). Prevalence was higher for older individuals, particularly in urban women (161.2 cases per 100,000, 95% CrI 148.6-175.0). Prevalence was lowest in young men (in rural areas, as low as 2.8 cases per 100,000, 95% CrI 1.4-4.8). In general, no single algorithm was very sensitive, with point estimates for sensitivity ranging from 20-73%.

CONCLUSION

We found marked differences in SSc prevalence according to age, sex, and region. In general, no single case ascertainment approach was very sensitive for SSc. Therefore, using data from multiple sources, with adjustment for the imperfect nature of each, is an important strategy in population-based studies of SSc and similar conditions.

Lupus and cancer

Individuals with systemic lupus erythematosus (SLE) have an increased susceptibility to certain types of cancer. Of particular concern are haematologic malignancies, specifically non-Hodgkin lymphoma, where a three- to four-fold increased risk is seen in SLE, compared with the general population. There is some evidence that immunosuppressive exposures play a role, although there appear to be other factors driving the risk. Lupus disease activity, with resultant dysregulated lymphocyte proliferation, may itself be a mediator of the association between SLE and lymphoma. Aside from haematologic malignancy risk, lung cancer also is increased in SLE compared with the general population, and smoking likely drives this risk in large part. Last but not least, cervical dysplasia is a concern in women with SLE, particularly with exposure to immunosuppressants; routine screening for this complication should not be neglected.

The relationship between renal activity and quality of life in systemic lupus erythematosus

OBJECTIVE

To evaluate the relationship between renal activity and quality of life (QOL) in patients with systemic lupus erythematosus (SLE).

METHODS

Three hundred eighty-six patients completed annual Medical Outcomes Study Short Form-36 questionnaires and physicians completed the SLE Disease Activity Index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. Concurrent association between renal activity and QOL was evaluated through regression models that adjusted for demographics and nonrenal disease activity and nonrenal damage. To characterize the longitudinal relationship between change in renal activity and change in QOL, all renal activity and QOL data over the entire study were used to estimate a linear trend within each individual patient through hierarchical modeling.

RESULTS

In the regression model that assessed the association between renal activity and QOL, on average, each additional renal activity item fulfilled was associated with a 2.04-unit (95% CI 0.88, 3.24) decrease in the physical function subscale, a 5.28-unit (95% CI 2.76, 7.76) decrease in the role-physical subscale, a 2.24-unit (95% CI 0.72, 3.80) decrease in the social function subscale, and a 1.16-unit (95% CI 0.60, 1.72) decrease in the physical component summary score. In the hierarchical model, no association was observed between changes in renal activity and QOL.

CONCLUSION

Patients with SLE and active renal disease concurrently experience a slightly poorer QOL than those without renal disease, especially in the physical domains. Because the confidence intervals were wide, we could not accurately estimate whether a longitudinal change in renal activity was associated with a change in QOL.

The cost of systemic sclerosis

OBJECTIVE

To assess costs related to systemic sclerosis (SSc) and their determinants.

METHODS

The Canadian Scleroderma Research Group is comprised of 15 centers contributing to a registry of adult patients with SSc. Available cross-sectional data included clinical variables and standardized measures of health resource use and time loss. Annualized averages of direct medical costs were calculated by multiplying health service utilization levels by the appropriate unit prices, determined from government fee schedules, professional associations, and other sources. Indirect costs were calculated from the subjects' self-reported time loss related to illness and to seeking health care, as well as caregiver time losses. Costs were represented in 2007 Canadian dollars.

RESULTS

In the sample of 457 patients with SSc, the average direct cost per patient was $5,038 per year (95% confidence interval [95% CI] $4,400, $5,676). Regarding indirect costs, the value of potential productivity loss related to paid labor was estimated at an average of $5,345 per patient per year (95% CI $4,598, $6,092), and the cost of lost productivity related to unpaid labor contributed another $8,070 per patient annually. The average total annual cost was estimated at $18,453 (95% CI $16,598, $20,308) per patient. Total annual costs were strongly associated with younger age, greater disease severity, and poorer health status.

CONCLUSION

Costs related to SSc are considerable, and there is a high impact of disease severity and health status on economic burden.

Application of a nomogram for exercise capacity in women with systemic lupus erythematosus

The aim of this study is to examine the exercise capacity in women with systemic lupus erythematosus (SLE). Women with SLE underwent exercise testing; their performance was compared to nomogram predictions. We assessed the potential effects of disease activity and cumulative damage on exercise capacity. We evaluated 52 female SLE patients aged >35 years. The mean workload achieved was somewhat higher than the nomogram predictions. However, over one fifth of the women performed at a very poor level, which in the general population is associated with a twofold increased risk of cardiovascular disease. Compared to other subjects, participants who did poorly tended toward higher disease activity, higher body mass index, and greater smoking prevalence, although the results were not definitive. Exercise testing may be used to identify a subpopulation of lupus patients with a low level of fitness. Extrapolating from general population data, these individuals are likely at particular risk for cardiovascular disease and may, therefore, benefit the most from aggressive cardiovascular risk factor reduction.

Use of methylene blue for catecholamine-refractory vasoplegia from protamine and aprotinin

We present two cases of catecholamine-refractory and vasopressin-refractory vasoplegic syndrome associated with intraoperative anaphylaxis during cardiac surgery. One case was related to the administration of protamine and the other case to the administration of aprotinin. Both cases were successfully managed using intravenous methylene blue. The use of methylene blue blocks accumulation of cyclic guanosine monophosphate by competitively inhibiting the enzyme guanylate cyclase. This results in reduced responsiveness of the vasculature to cyclic guanosine monophosphate-mediated vasodilators, such as nitric oxide. This report provides a description of severe anaphylaxis induced by different agents, in which the use of methylene blue was associated with a significant clinical response.

Systemic lupus international collaborating clinics renal activity/response exercise: development of a renal activity score and renal response index

OBJECTIVE

To develop a measure of renal activity in systemic lupus erythematosus and use it to develop a renal response index.

METHODS

Abstracted data from the medical records of 215 patients with lupus nephritis were sent to 8 nephrologists and 29 rheumatologists for rating. Seven nephrologists and 22 rheumatologists completed the ratings. Each physician rated each patient visit with respect to renal disease activity (none, mild, moderate, or severe). Using the most commonly selected rating for each patient as the gold standard, stepwise regression modeling was performed to identify the variables most related to renal disease activity, and these variables were then used to create an activity score. This activity score could then be applied to 2 consecutive visits to define a renal response index.

RESULTS

The renal activity score was computed as follows: proteinuria 0.5-1 gm/day (3 points), proteinuria 0.5-1 gm/day = 3 points, proteinuria >1-3 gm/day = 5 points, proteinuria >3 gm/day = 11 points, [corrected] urine red blood cell count > = 5/hpf = 3 points, [corrected] urine white blood cell count > or = 5/hpf = 1 point. [corrected] The chance-adjusted agreement between the renal response index derived from the activity score applied to the paired visits and the plurality physician response rating was 0.69 (95% confidence interval 0.59-0.79).

CONCLUSION

Ratings derived from this index for rating of renal response showed reasonable agreement with physician ratings in a pilot study. The index will require further refinement, testing, and validation. A data-driven approach to create renal activity and renal response indices will be useful in both clinical care and research settings.

Systemic lupus international collaborating clinics renal activity/response exercise: comparison of agreement in rating renal response

OBJECTIVE

To assess the degree to which physicians agree with each other and with ratings obtained with 3 existing responder indices, in rating the response to treatment of lupus nephritis.

METHODS

Lupus nephritis patient medical records from 125 pairs of visits (6 months apart) were used to create renal response scenarios. Seven nephrologists and 22 rheumatologists rated each scenario as demonstrating complete response, partial response, same, or worsening. The plurality (most frequent) rating of renal response by the physicians was compared with the calculated score from the renal component of the British Isles Lupus Assessment Group (BILAG) index (original and updated [2004] version) and of the Responder Index for Lupus Erythematosus (RIFLE). The degree of agreement among the physicians was assessed by calculating intraclass correlation coefficients (ICCs). The degree of agreement between the plurality physician rating and ratings obtained with the established response indices was assessed using the kappa statistic.

RESULTS

The ICC among all physicians was 0.64 (0.62 for nephrologists and 0.67 for rheumatologists). The chance-adjusted measure of agreement (kappa coefficient) between the plurality physician rating and the calculated score obtained using established indexes was 0.50 (95% confidence interval [95% CI] 0.38-0.61) for the RIFLE, 0.14 (95% CI 0.03-0.25) for the original BILAG, and 0.23 (95% CI 0.21-0.44) for the BILAG 2004.

CONCLUSION

These findings indicate that rheumatologists as a group and nephrologists as a group have equal agreement in their rating of renal response. There was moderate agreement between plurality physician ratings and ratings obtained using the renal component of the RIFLE. Ratings of response using an index based on the original BILAG did not have good agreement with the plurality physician rating.

Hematologic malignant neoplasms after drug exposure in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis is a severe inflammatory polyarthritis that requires long-term treatment with disease-modifying antirheumatic drugs. There is increasing concern about the influence of rheumatoid arthritis therapy on the risk for hematologic malignant neoplasms.

METHODS

We used a case-control design nested in a cohort of 23,810 patients with rheumatoid arthritis assembled from administrative databases covering the population of Quebec, Canada. The study was carried out from January 1, 1980, through December 31, 2003. Case patients having hematologic malignant neoplasms were ascertained from physician billing and hospitalization records; each case patient was matched for age and sex with 10 control subjects. Adjusting for clinical variables and concomitant medications, we used conditional logistic regression to analyze potential associations between disease-modifying antirheumatic drug exposures and risk for hematologic malignant neoplasms. We estimated rate ratios attributable to each disease-modifying antirheumatic drug exposure.

RESULTS

During the study, hematologic malignant neoplasms developed in 619 patients, including lymphomas in 346 patients, leukemia in 178 patients, and multiple myelomas in 95 patients. The unadjusted rate ratios for hematologic malignant neoplasms after drug exposures were as follows: methotrexate, 1.18 (95% confidence interval [CI], 0.99-1.40); azathioprine, 1.44 (95% CI, 1.01-2.03); and cyclophosphamide, 2.21 (95% CI, 1.52-3.20). Because biologic agents first appeared in the Régie d'Assurance Maladie du Quebec formulary in 2002, there were few exposures to these drugs. Adjusted estimates suggested that hematologic cancer risk was most elevated after exposure to cyclophosphamide (rate ratio, 1.84; 95% CI, 1.24-2.73). For lymphomas only, the adjusted rate ratio after cyclophosphamide exposure was 2.12 (95% CI, 1.33-3.54).

CONCLUSIONS

In this large cohort of patients with rheumatoid arthritis, the greatest relative risk for hematologic malignant neoplasms was noted after use of cyclophosphamide. Assessments of risk related to newer and emerging therapies should carefully consider previous and concomitant medication exposures.

SLE patients with renal damage incur higher health care costs

OBJECTIVES

To compare costs and quality of life (QoL) between SLE patients with and without renal damage.

METHODS

Seven hundred and fifteen patients were surveyed semi-annually over 4 yrs on health care use and productivity loss and annually on QoL. Cumulative direct and indirect costs (2006 Canadian dollars) and QoL (average annual change in SF-36) were compared between patients with and without renal damage [Systemic Lupus International Collaborating Clinics/ACR Damage Index (SLICC/ACR DI)] using simultaneous regressions.

RESULTS

At study conclusion, for patients with the renal subscale of the SLICC/ACR DI = 0 (n = 634), 1 (n = 54), 2 (n = 15) and 3 (n = 12), mean 4-yr cumulative direct costs per patient (95% CI) were $20,337 ($18,815, $21,858), $27,869 ($19,230, $36,509), $51,191 ($23,463, $78,919) and $99,544 ($57,102, $141,987), respectively. In a regression where the renal subscale of the SLICC/ACR DI was a single indicator variable, on average (95% CI), each unit increase in renal damage was associated with a 24% (15%, 33%) increase in direct costs. In a regression where each level in the renal subscale was an indicator variable, patients with end-stage renal disease incurred 103% (65%, 141%) higher direct costs than those without renal damage. Cumulative indirect costs and annual change in the SF-36 summary scores did not differ between patients.

CONCLUSIONS

SLE patients with renal damage incurred higher direct costs, but did not experience a poorer QoL. QoL may be more influenced by concurrent renal activity than accumulated renal damage, which can occur at any time and patients may gradually habituate to their compromised health state.