Daphne Guh

The incidence of co-morbidities related to obesity and overweight: A systematic review and meta-analysis

BackgroundOverweight and obese persons are at risk of a number of medical conditions which can lead to further morbidity and mortality. The primary objective of this study is to provide an estimate of the incidence of each co-morbidity related to obesity and overweight using a meta-analysis.MethodsA literature search for the twenty co-morbidities identified in a preliminary search was conducted in Medline and Embase (Jan 2007). Studies meeting the inclusion criteria (prospective cohort studies of sufficient size reporting risk estimate based on the incidence of disease) were extracted. Study-specific unadjusted relative risks (RRs) on the log scale comparing overweight with normal and obese with normal were weighted by the inverse of their corresponding variances to obtain a pooled RR with 95% confidence intervals (CI).ResultsA total of 89 relevant studies were identified. The review found evidence for 18 co-morbidities which met the inclusion criteria. The meta-analysis determined statistically significant associations for overweight with the incidence of type II diabetes, all cancers except esophageal (female), pancreatic and prostate cancer, all cardiovascular diseases (except congestive heart failure), asthma, gallbladder disease, osteoarthritis and chronic back pain. We noted the strongest association between overweight defined by body mass index (BMI) and the incidence of type II diabetes in females (RR = 3.92 (95% CI: 3.10–4.97)). Statistically significant associations with obesity were found with the incidence of type II diabetes, all cancers except esophageal and prostate cancer, all cardiovascular diseases, asthma, gallbladder disease, osteoarthritis and chronic back pain. Obesity defined by BMI was also most strongly associated with the incidence of type II diabetes in females (12.41 (9.03–17.06)).ConclusionBoth overweight and obesity are associated with the incidence of multiple co-morbidities including type II diabetes, cancer and cardiovascular diseases. Maintenance of a healthy weight could be important in the prevention of the large disease burden in the future. Further studies are needed to explore the biological mechanisms that link overweight and obesity with these co-morbidities.

Diacetylmorphine versus Methadone for the Treatment of Opioid Addiction

BACKGROUND Studies in Europe have suggested that injectable diacetylmorphine, the active ingredient in heroin, can be an effective adjunctive treatment for chronic, relapsing opioid dependence. METHODS In an open-label, phase 3, randomized, controlled trial in Canada, we compared injectable diacetylmorphine with oral methadone maintenance therapy in patients with opioid dependence that was refractory to treatment. Long-term users of injectable heroin who had not benefited from at least two previous attempts at treatment for addiction (including at least one methadone treatment) were randomly assigned to receive methadone (111 patients) or diacetylmorphine (115 patients). The primary outcomes, assessed at 12 months, were retention in addiction treatment or drug-free status and a reduction in illicit-drug use or other illegal activity according to the European Addiction Severity Index. RESULTS The primary outcomes were determined in 95.2% of the participants. On the basis of an intention-to-treat analysis, the rate of retention in addiction treatment in the diacetylmorphine group was 87.8%, as compared with 54.1% in the methadone group (rate ratio for retention, 1.62; 95% confidence interval [CI], 1.35 to 1.95; P<0.001). The reduction in rates of illicit-drug use or other illegal activity was 67.0% in the diacetylmorphine group and 47.7% in the methadone group (rate ratio, 1.40; 95% CI, 1.11 to 1.77; P=0.004). The most common serious adverse events associated with diacetylmorphine injections were overdoses (in 10 patients) and seizures (in 6 patients). CONCLUSIONS Injectable diacetylmorphine was more effective than oral methadone. Because of a risk of overdoses and seizures, diacetylmorphine maintenance therapy should be delivered in settings where prompt medical intervention is available. (ClinicalTrials.gov number, NCT00175357.)

Obesity and overweight in Canada: an updated cost-of-illness study.

This study is to update the estimates of the economic burden of illness because of overweight and obesity in Canada by incorporating the increase in prevalence of overweight and obesity, findings of new related comorbidities and rise in the national healthcare expenditure. The burden was estimated from a societal perspective using the prevalence‐based cost‐of‐illness methodology. Results from a literature review of the risks of 18 related comorbidities were combined with prevalence of overweight and obesity in Canada to estimate the extent to which each comorbidity is attributable to overweight and obesity. The direct costs were extracted from the National Health Expenditure Database and allocated to each comorbidity using weights principally from the Economic Burden of Illness in Canada. The study showed that the total direct costs attributable to overweight and obesity in Canada were

Use of nonbiologic disease-modifying antirheumatic drugs and risk of infection in patients with rheumatoid arthritis

6.0 billion in 2006, with 66% attributable to obesity. This corresponds to 4.1% of the total health expenditures in Canada in 2006. The inclusion of newly identified comorbidities increased the direct cost estimates of obesity by 25%, while the rise in national healthcare expenditure accounted for a 19% increase. Policies to reduce being overweight and obese could potentially save the Canadian healthcare system millions of dollars.

A comparison of four indirect methods of assessing utility values in rheumatoid arthritis.

OBJECTIVE Rheumatoid arthritis (RA) is associated with increased frequency of and mortality from infections, which may be related to host factors, RA itself, inflammation, or medication side effects. This study was undertaken to determine the effect of nonbiologic disease-modifying antirheumatic drugs (DMARDs) on infection risk in RA. METHODS We performed a retrospective, longitudinal study of a population-based RA cohort in British Columbia, Canada, followed from January 1996 to March 2003 using administrative data. We evaluated mild infections (requiring a physician visit or antibiotics) and serious infections (requiring or complicating hospitalization). Adjusted risk of mild and serious infections associated with DMARD exposure was estimated using generalized estimating equation extension of multivariate Poisson regression models, after adjusting for baseline covariates (age, sex, RA duration, socioeconomic status) and time-dependent covariates (corticosteroids, comorbidity, prior infections). RESULTS A total of 27,710 individuals with RA provided 162,710 person-years of followup. Of these, 25,608 (92%) had at least 1 mild infection and 4,941 (18%) had at least 1 serious infection. Use of DMARDs without corticosteroids was associated with a small decrease in mild infection risk of statistical significance but unclear clinical significance (adjusted rate ratio [RR] 0.90, 95% confidence interval [95% CI] 0.88-0.93 relative to no corticosteroid or DMARD use). Use of DMARDs without corticosteroids was not associated with increased serious infection risk (adjusted RR 0.92, 95% CI 0.85-1.0). Use of corticosteroids increased the risk of mild and serious infections. CONCLUSION Our results indicate that use of nonbiologic DMARDs, including methotrexate, does not increase the risk of infection in RA, whereas use of corticosteroids does. This has important implications for counseling individuals with RA concerning risks and benefits of DMARDs.

A dog's breakfast: prescription drug coverage varies widely across Canada.

Objectives:Utility scores can be assessed indirectly using preference-based instruments and used as weightings for quality-adjusted life years in economic analyses. It is not clear whether available instruments yield similar results or what domains of health are contributing to the overall score in a sample of patients with rheumatoid arthritis (RA). Subjects:Our study included 313 individuals with rheumatologist-confirmed RA. Measures:A self-completed survey that permitted scoring of 4 indirect utility instruments (the Health Utilities Index Mark 2 and 3 (HUI-2 and HUI-3), the EuroQoL (EQ-5D), and the Short Form 6D (SF-6D) was the basis of our study. Results:Mean (standard deviation) global utility scores were 0.63 (0.24) for the SF-6D, 0.66 (0.13) for the EQ-5D, 0.71 (0.19) for the HUI-2, and 0.53 (0.29) for the HUI-3 (P = 0.02 by repeated-measures analysis of variance). The intraclass correlation across all the indices was 0.67 (95% confidence interval 0.62–0.71). Bland-Altman plots revealed that agreement among instruments was poor at lower utility values. In this elderly RA sample, all of the global utilities mostly measured functional ability and pain. Conclusions:There are significant differences in utilities obtained from different indirect methods. Agreement among the instruments was moderate but poorer at lower utilities. It is unlikely that these utility values, if used as the weightings for quality-adjusted life years, would result in comparable estimates.

Are indirect utility measures reliable and responsive in rheumatoid arthritis patients

Background.Each province in Canada independently assesses drugs for their reimbursement eligibility. Publicly funded access to specific drugs is therefore dependent on province of residence. Objective.Evaluate the variability of access and its determinants for publicly available prescription drugs across Canada, and discuss the feasibility of implementing a national plan. Methods.For a sample of 58 drugs receiving Health Protection Branch approval in Canada between 01/01/1996 and 12/31/1997, all provinces were surveyed about their formulary inclusion/exclusion decision. Kappa values were estimated to measure concordance between provincial coverage decisions. Logistic analysis using Generalized Estimating Equations was used to assess the impact of key features of provincial plans on the decision. Results.Among the 58 drugs, 5 (9%) were included in all 10 and 14 (24%) by at least 8 provincial formularies. None were e-cluded by all the provinces. Concordance rates among provinces were low (overall &kgr;-like statistic = 0.20 and range of pairwise &kgr; = -0.11 to 0.64). Logistic regression showed that therapeutic category, price ratio to comparator, the integration of public with private coverage, and the e-istence of ability-to-pay criteria were significant determinants of the inclusion decision. Conclusions.Findings show that public access to the same prescription medications differs widely across provinces. If Canada were to adopt a “National” plan without disrupting current individual prescriptions, all currently funded drugs in each province would have to be “grandfathered” and included in the new National formulary. Such an all-inclusive list would also make such a plan unaffordable.

HIV-positive injection drug users who leave the hospital against medical advice: the mitigating role of methadone and social support.

Background: Preference-based, generic measures are increasingly being used to measure quality of life and as sources for quality weights in the estimation of Quality Adjusted Life Years (QALYs) in rheumatoid arthritis (RA). However, among the most commonly used instruments (the Health Utilities Index 2 and 3 [HUI2 and HUI3], the EuroQoL-5D [EQ-5D], and the Short Form-6D [SF-6D], there has been little comparative research. Therefore, we examined the reliability and responsiveness of these measures and the Rheumatoid Arthritis Quality of Life (RAQoL) and the Health Assessment Questionnaire (HAQ) in a sample of RA patients. Major findings: Test–retest reliability was acceptable for all of the instruments with the exception of the EQ-5D. Using two external criteria to define change (a patient transition question and categories of the patient global assessment of disease activity VAS), the RAQoL was the most responsive of the instruments. For the indirect utility instruments, the HUI3 and the SF-6D were the most responsive for measuring positive change. On average, for patients whose RA improved, the absolute change was highest for the HUI3. Conclusions: The HUI3 and the SF-6D appear to be the most responsive of the preference-based instruments in RA. However, differences in the magnitude of the absolute change scores have important implications for cost-effectiveness analyses.

Cost-effectiveness of diacetylmorphine versus methadone for chronic opioid dependence refractory to treatment

BackgroundLeaving the hospital against medical advice has been associated with increased morbidity and readmission. Factors associated with the risk of leaving against medical advice among HIV/AIDS patients or injection drug users have not been examined in detail. ObjectivesTo examine the clinical and social factors associated with leaving against medical advice (AMA) from a specialized HIV/AIDS ward among patients who reported a history of injection drug use. MethodsAll patients with a history of injection drug use admitted to the HIV/AIDS ward at St. Pauls Hospital, Vancouver, British Columbia (the largest specialized HIV/AIDS hospital ward in Canada) between April 1997 and October 2000 were reviewed retrospectively. A multivariate logistic regression model utilizing a generalized estimating equation algorithm identified factors associated with leaving the hospital AMA. ResultsOf the 1056 hospital admissions to the HIV/AIDS ward by patients with a history of injection drug use, 263 (24.9%) resulted in leaving the hospital AMA. Independent positive predictors of leaving AMA included recent injection drug use (adjusted odds ratio [AOR] = 2.08, 95% confidence interval [CI]: 1.41–3.07) and aboriginal ethnicity (AOR = 1.55, 95% CI: 1.05–2.28). Discharge AMA was also more likely to occur on weekends (AOR = 2.27, 95% CI: 1.49–3.48) and on days when social assistance payments were issued (AOR = 2.95, 95% CI: 1.70–5.10). Factors that independently reduced the odds of hospital discharge AMA included in-hospital methadone use (AOR = 0.49, 95% CI: 0.32–0.76), social support (AOR = 0.33, 95% CI: 0.21–0.51), and older age (per 10-year increment, AOR = 0.56, 95% CI: 0.43–0.73). ConclusionsAmong HIV-positive patients with a history of injection drug use, the odds of leaving the hospital AMA were reduced for subjects who received inpatient methadone treatment, were of older age, or had social supports. Addiction treatment and interventions that enhance social supports in marginalized populations at risk for hospital discharge AMA should be further explored.

When patients have to pay a share of drug costs: effects on frequency of physician visits, hospital admissions and filling of prescriptions

Background: Although diacetylmorphine has been proven to be more effective than methadone maintenance treatment for opioid dependence, its direct costs are higher. We compared the cost-effectiveness of diacetylmorphine and methadone maintenance treatment for chronic opioid dependence refractory to treatment. Methods: We constructed a semi-Markov cohort model using data from the North American Opiate Medication Initiative trial, supplemented with administrative data for the province of British Columbia and other published data, to capture the chronic, recurrent nature of opioid dependence. We calculated incremental cost-effectiveness ratios to compare diacetylmorphine and methadone over 1-, 5-, 10-year and lifetime horizons. Results: Diacetylmorphine was found to be a dominant strategy over methadone maintenance treatment in each of the time horizons. Over a lifetime horizon, our model showed that people receiving methadone gained 7.46 discounted quality-adjusted life-years (QALYs) on average (95% credibility interval [CI] 6.91–8.01) and generated a societal cost of