Stratifying the risks of venous thromboembolism in the lateral skull base surgery using Caprini risk assessment model.

PURPOSE: To analyze and stratify the possible risk factors of venous thromboembolism (VTE) in lateral skull base surgery (LSBS) using the Caprini risk assessment model. METHODS: In a single center, a retrospective study was conducted with patients who underwent LSBS from June 2016 to August 2021. The clinical characteristics and blood chemistry tests were collected. The incidence of VTE within 30 days of surgery was recorded. The Caprini risk score was calculated to assess the postoperative VTE risk. RESULTS: Among the 123 patients in this study, the VTE incidence within 30 postoperative days was 8.9%. The total Caprini risk score in VTE patients (5.6 ± 1.9 points) was significantly higher than that of non-VTE patients (4.6 ± 1.4 points; p = 0.028). The binary logistic regression showed the total Caprini score as the only independent indicator of postoperative VTE. The receiver operating characteristic curve analysis showed that the Caprini score at 6.5 points had low sensitivity (36.4%) but high specificity (91.1%), with the largest area under the curve being 0.659. The VTE rate was significantly higher in patients with a total Caprini score ≥ 7 points (28.6%) compared to those with a total Caprini score ≤ 6 points (7.3%; p = 0.022). CONCLUSION: LSBS patients have a high risk of developing postoperative VTE. Patients with a Caprini score ≥ 7 points had a significantly higher risk of developing VTE after LSBS. The Caprini risk system was useful in assessing the VTE risk in LSBS. However, more data, calibration, and validation are necessary to establish an exclusive Caprini risk system for LSBS.

Spatiotemporal Variations of Carbon Emissions and Their Driving Factors in the Yellow River Basin.

The Yellow River Basin (YRB) is a significant area of economic development and ecological protection in China. Scientifically clarifying the spatiotemporal patterns of carbon emissions and their driving factors is of great significance. Using the methods of spatial autocorrelation analysis, hot-spot analysis, and a geodetector, the analysis framework of spatiotemporal differentiation and the driving factors of carbon emissions in the YRB was constructed in this paper from three aspects: natural environment, social economy, and regional policy. Three main results were found: (1) The carbon emissions in the YRB increased gradually from 2000 to 2020, and the growth rates of carbon emissions in the different river reaches were upper reaches > middle reaches > lower reaches. (2) Carbon emissions have an obvious spatial clustering character from 2000-2020, when hot spots were concentrated in the transition area from the Inner Mongolia Plateau to the Loess Plateau. The cold spots of carbon emissions tended to be concentrated in the junction area of Qinghai, Gansu, and Shaanxi. (3) From 2000 to 2020, the driving factors of spatial differentiation of carbon emissions in the YRB and its different reaches tended to be diversified, so the impacts of socioeconomic factors increased, while the impacts of natural environmental factors decreased. The influence of the interactions of each driving factor showed double factor enhancement and nonlinear enhancement. This study will provide a scientific reference for green and low-carbon development, emphasizing the need to pay more attention to environmental protection, develop the green economy vigorously, and promote the economic cycle, so as to achieve green development and reduce carbon emissions.

The Impact of Tiered-Pricing Framework on Generic Entry in Canada.

BACKGROUND: Generic drug prices have been capped at specified percentages of the interchangeable branded drug's price by the Canadian provincial public drug plans since 1993. The Pan-Canadian Pharmaceutical Alliance, formed as a coalition by the provinces/territories in Canada, implemented an alternative approach, a tiered-pricing framework (TPF) for new generic drugs on April 1, 2014, under which the percentage varies with the number of generic firms in each market. We evaluate the impact of the TPF on generic entry, ie, listing in public drug plans in Canada. METHODS: Our study compared the pre-TPF period (01/01/2012-03/31/2014) with the TPF period (04/01/2014- 06/30/2016). Prescription drugs from nine provincial public drug plans were grouped into a "market" if they had the same active ingredient and strength, route of administration, and dosage form. Each "market" was contestable by generics and met the eligibility criteria for TPF. At the "market" level, Cox proportional-hazards models with time-varying covariates were used to measure the impact of the TPF on the first generic listing in any provincial public drug plan in Canada relative to the first launch date worldwide. RESULTS: A total of 189 markets in Canada were selected for the analyses. Generic drugs in small markets were more likely to be listed in Canada during the TPF period compared to the pre-TPF period (hazard ratio [HR], 95% CI: 3.81, 1.51-9.62). There was no significant difference in generic drug listings in large markets between the two policy periods. CONCLUSION: TPF speeds up generic entry in small markets and generates the benefits of generic competition while avoiding the pitfalls of the previously employed price-cap regulations.

Factors associated with drug shortages in Canada: a retrospective cohort study.

BACKGROUND: To monitor the magnitude of the drug shortage problem in Canada, since 2017, Health Canada has required manufacturers to report drug shortages. This study aimed to identify the factors associated with drug shortages in Canada. METHODS: We conducted a retrospective cohort study of all prescription drugs available on the market between Mar. 14, 2017, and Sept. 12, 2018, in Canada. All drugs of the same active ingredient, dosage form, route of administration and strength were grouped into a "market." Our main outcome was shortages at the market level, determined using the Drug Shortages Canada database. We used logistic regression to identify associated factors such as market structure, route or dosage form, and Anatomic Therapeutic Chemical (ATC) classification. RESULTS: Among the 3470 markets included in our analysis, 13.3% were reported to be in shortage. Markets with a single generic manufacturer were more likely to be in shortage than other markets. Markets with oral nonsolid route or dosage form were more likely to be in shortage than those that were oral solid with regular release (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.11 to 2.49). Markets for sensory organs were more likely to be in shortage than most other ATC classes. Markets with a higher proportion of drugs covered by public insurance programs were more likely to be in shortage (OR 1.03, 95% CI 1.00 to 1.05 per 10% increase). INTERPRETATION: Markets with a single generic manufacturer were most likely to be in shortage. To ensure the security of drug supply, governments should be vigilant in monitoring markets with a single generic manufacturer, with complex manufacturing processes, with higher demand from public programs or those that are in certain ATC classes.

Do Biologic Therapies for Rheumatoid Arthritis Offset Treatment-Related Resource Utilization and Cost? A Review of the Literature and an Instrumental Variable Analysis.

PURPOSE OF REVIEW: One justification for using expensive biologic therapy in rheumatoid arthritis (RA) has been that it can reduce future healthcare utilization such as joint surgeries and physician visits. However, the evidence to support this assertion is unclear. We conducted a review of the literature for studies which have analyzed the trends in resource use of RA patients, and then undertook a retrospective observational analysis of a Canadian administrative database using instrumental variable methods. RECENT FINDINGS: Our review found a trend in reduced resource utilization prior to the introduction of biologics and no evidence that biologic therapies have specifically contributed to this reduction. Our observational analysis, which overcame some of the epidemiological challenges with determining the influence of biologics on resource utilization, found a possible reduction in other medications but possible increases rather than decreases in physician visits and hospitalizations. However, our sample was not sufficiently large to make definitive conclusions. Over 15 years since the introduction of biologics for RA, no evidence exists supporting the assumption that biologic therapies reduce future healthcare utilization. While such a question is challenging to generate evidence for, and so an absence of evidence does not suggest that the hypothesis is incorrect, an instrumental variable analysis using sufficient data could provide definitive evidence.

Triple Therapy Versus Biologic Therapy for Active Rheumatoid Arthritis: A Cost-Effectiveness Analysis.

Background: The RACAT (Rheumatoid Arthritis Comparison of Active Therapies) trial found triple therapy to be noninferior to etanercept-methotrexate in patients with active rheumatoid arthritis (RA). Objective: To determine the cost-effectiveness of etanercept-methotrexate versus triple therapy as a first-line strategy. Design: A within-trial analysis based on the 353 participants in the RACAT trial and a lifetime analysis that extrapolated costs and outcomes by using a decision analytic cohort model. Data Sources: The RACAT trial and sources from the literature. Target Population: Patients with active RA despite at least 12 weeks of methotrexate therapy. Time Horizon: 24 weeks and lifetime. Perspective: Societal and Medicare. Intervention: Etanercept-methotrexate first versus triple therapy first. Outcome Measures: Incremental costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). Results of Base-Case Analysis: The within-trial analysis found that etanercept-methotrexate as first-line therapy provided marginally more QALYs but accumulated substantially higher drug costs. Differences in other costs between strategies were negligible. The ICERs for first-line etanercept-methotrexate and triple therapy were $2.7 million per QALY and $0.98 million per QALY over 24 and 48 weeks, respectively. The lifetime analysis suggested that first-line etanercept-methotrexate would result in 0.15 additional lifetime QALY, but this gain would cost an incremental $77 290, leading to an ICER of $521 520 per QALY per patient. Results of Sensitivity Analysis: Considering a long-term perspective, an initial strategy of etanercept-methotrexate and biologics with similar cost and efficacy is unlikely to be cost-effective compared with using triple therapy first, even under optimistic assumptions. Limitation: Data on the long-term benefit of triple therapy are uncertain. Conclusion: Initiating biologic therapy without trying triple therapy first increases costs while providing minimal incremental benefit. Primary Funding Source: The Cooperative Studies Program, Department of Veterans Affairs Office of Research and Development, Canadian Institutes for Health Research, and an interagency agreement with the National Institutes of Health-American Recovery and Reinvestment Act.

Valuing productivity loss due to absenteeism: firm-level evidence from a Canadian linked employer-employee survey.

In health economic evaluation studies, to value productivity loss due to absenteeism, existing methods use wages as a proxy value for marginal productivity. This study is the first to test the equality between wage and marginal productivity losses due to absenteeism separately for team workers and non-team workers. Our estimates are based on linked employer-employee data from Canada. Results indicate that team workers are more productive and earn higher wages than non-team workers. However, the productivity gap between these two groups is considerably larger than the wage gap. In small firms, employee absenteeism results in lower productivity and wages, and the marginal productivity loss due to team worker absenteeism is significantly higher than the wage loss. No similar wage-productivity gap exists for large firms. Our findings suggest that productivity loss or gain is most likely to be underestimated when valued according to wages for team workers. The findings help to value the burden of illness-related absenteeism. This is important for economic evaluations that seek to measure the productivity gain or loss of a health care technology or intervention, which in turn can impact policy makers' funding decisions.

The impact of price-cap regulations on market entry by generic pharmaceutical firms.

BACKGROUND: In 1998, the province of Ontario, Canada implemented price-cap '70/90' regulations: the first generic must be priced at ≤70% of the associated brand-name price and subsequent generics must be priced at ≤90% of the first generics' price. The price-cap was further lowered to 50% in 2006 and 25% in 2010 for all generic drugs regardless of the first or subsequent generic entrants. This study assessed the impact of such price-cap regulations on market entry by generic firms using the formulary database from 9 provinces (January 2004-March 2013). METHODS: A logistic regression was estimated to compare the probability of entry during the three policy periods in Ontario ('70/90', '25', versus '50'). Since different price-caps were subsequently introduced in other provinces, Alberta, British Columbia, New Brunswick and Saskatchewan, difference-in-differences was used to compare market entry. RESULTS: In Ontario, compared with the period '50', generic firms were 76% and 63% less likely to enter markets in the periods '25' and '70/90', respectively. The difference-in-differences showed that the entry probability decreased the most in Ontario during the '25' period from the '50' period. CONCLUSION: Lowering the price-cap level to 25% leads to a significantly lower probability of market entry by generic firms.

The Impact of Price-cap Regulations on Exit by Generic Pharmaceutical Firms.

BACKGROUND: In 1998, the Province of Ontario in Canada adopted price-cap "70/90" regulations whereby the first generic entrant was required to be priced at ≤70% of the associated brand-name product and subsequent generics were priced at ≤90% of the first generic price. The price-caps were further lowered to 50% in 2006 and 25% in 2010. This study assessed the impact of such price-cap regulations on exit by generic drug firms. METHODS: Formulary (2003-2012) listings of prescription drugs covered under the Ontario Drug Benefit program were used. The formulary tracks the "status" (on formulary, discontinued by manufacturer, and delisted for other reasons) for each drug. Markets were defined based on unique active ingredient and form within Ontario. Firm exit occurred when a manufacturer discontinued all its generic drugs within a market. The exit rate was defined as the number of generic firm-market exits divided by total generic firm-market follow-up years. Poisson regression was used to compare the exit rates during the 3 policy periods ("25," "50," and "70/90"). RESULTS: A total of 1126 generic manufacturers paired with 290 markets were identified. The exit rate ratio during the 25% price-cap period compared with the 70%/90% period was 2.42 (95% confidence interval, 1.56-3.77). A small manufacturer or a manufacturer in a market with ≥3 competitors or in an older market was more likely to exit. CONCLUSIONS: Lowering the price-cap level is associated with a higher incidence of generic firm exit from markets. Continuously reducing price-caps may have the unintended consequence of forcing generic firms to exit.

Estimating the monetary value of the annual productivity gained in patients with early rheumatoid arthritis receiving etanercept plus methotrexate: interim results from the PRIZE study.

OBJECTIVE: To measure and value the impact of combined etanercept (ETN) and methotrexate (MTX) therapy on work productivity in patients with early rheumatoid arthritis (RA) over 52 weeks. METHODS: MTX- and biological-naïve patients with RA (symptom onset ≤12 months; Disease Activity Score based on a 28-joint count (DAS28) >3.2) received open-label ETN50/MTX for 52 weeks. The Valuation of Lost Productivity (VOLP) questionnaire, measuring paid and unpaid work productivity impacts, was completed approximately every 13 weeks. Bootstrapping methods were used to test changes in VOLP outcomes over time. One-year productivity impacts were compared between responders (DAS28 ≤3.2) at week 13 and non-responders using zero-inflated models for time loss and two-part models for total costs of lost productivity. RESULTS: 196 patients were employed at baseline and had ≥1 follow-up with VOLP. Compared with baseline, at week 52, patients gained 33.4 h per 3 months in paid work and 4.2 h per week in unpaid work. Total monetary productivity gains were €1322 per 3 months. Over the 1-year period, responders gained paid (231 h) and unpaid work loss (122 h) compared with non-responders, which amounted to a gain of €3670 for responders. CONCLUSIONS: This is the first clinical trial to measure and value the impact of biological treatment on all the labour input components that affect overall productivity. Combination therapy with ETN50/MTX was associated with a significant productivity gain for patients with early RA who were still observed at week 52. Over the 1-year treatment period, responders at week 13 suffered significantly less productivity loss than non-responders suggesting this gain was related to treatment response. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number NCT00913458.

Illness related wage and productivity losses: Valuing 'presenteeism'.

One source of productivity loss due to illness is the reduced "quantity" or "quality" of labor input while working, often referred to as presenteeism. Illness-related presenteeism has been found to be potentially more costly than absenteeism. To value presenteeism, existing methods use wages as a proxy for marginal productivity at the firm level. However, wage may not equal marginal productivity in some scenarios. One instance is when a job involves team production and perfect substitutes for workers are not readily available. Using a Canadian linked employer-employee survey (2001-2005), we test whether relative wage equals relative marginal productivity among team workers and non-team workers with different frequencies of presenteeism (reduction at work due to illness). For the pooled cross-sectional estimates (2001, 2003, 2005) we obtain 13,755 observations with 6842 unique workplaces. There are 6490 observations for the first differences estimates from the odd years and 5263 observations for the first differences estimates from 2001 to 2002 and 2003 to 2004. We find that in both small and large firms, team workers with frequent reductions at work are less productive but earn similarly compared with non-team workers without reductions. We also find that in small firms, workers with occasional work reductions are more productive than workers without reductions, but the reverse is true in large firms. The study findings partially support the literature stating that productivity loss resulting from employee presenteeism could exceed wages if team work is involved.

Effect of management strategies and clinical status on costs of care for advanced HIV.

OBJECTIVES: To determine the association between preexisting characteristics and current health and the cost of different types of advanced human immunodeficiency virus (HIV) care. METHODS: Treatment-experienced patients failing highly active antiretroviral treatment (ART) in the United States, Canada, and the United Kingdom were factorial randomized to an antiretroviral-free period and ART intensification. Cost was estimated by multiplying patient-reported utilization by a unit cost. RESULTS: A total of 367 participants were followed for a mean of 15.3 quarters (range 1-26). Medication accounted for most (61.8%) of the $26,832 annual cost. Cost averaged $4147 per quarter for ART, $1981 for inpatient care, $580 for outpatient care, and $346 for other medications. Cost for inpatient stays, outpatient visits, and other medications was 171% higher (P <.01) and cost of ART was 32% lower (P <.01) when cluster of differentiation 4 (CD4) count was <50 cells/µL compared with periods when CD4 count was >200 cells/µL. Some baseline characteristics, including low CD4 count, high viral load, and HIV from injection drug use with hepatitis C coinfection, had a sustained effect on cost. CONCLUSIONS: The association between health status and cost depended on the type of care. Indicators of poor health were associated with higher inpatient and concomitant medication costs and lower cost for ART medication. Although ART has supplanted hospitalization as the most important cost in HIV care, some patients continue to incur high hospitalization costs in periods when they are using less ART. The cost of interventions to improve the use of ART might be offset by the reduction of other costs.

Optimal timing of influenza vaccination in patients with human immunodeficiency virus: a Markov cohort model based on serial study participant hemoagglutination inhibition titers.

BACKGROUND: Seasonal influenza vaccination offers one of the best population-level protections against influenza-like illness (ILI). For most people, a single dose prior to the flu season offers adequate immunogenicity. HIV+ patients, however, tend to exhibit a shorter period of clinical protection, and therefore may not retain immunogenicity for the entire season. Building on the work of Nosyk et al. (2011) that determined a single dose is the optimal dosing strategy for HIV+ patients, we investigate the optimal time to administer this vaccination. METHODS: Using data from the "single dose" treatment arm of an RCT conducted at 12 CIHR Canadian HIV Trials Network sites we estimated semimonthly clinical seroprotection levels for a cohort (N=93) based on HAI titer levels. These estimates were combined with CDC attack rate data for the three main strains of seasonal influenza to estimate instances of ILI over different vaccination timing strategies. Using bootstrap resampling of the cohort, nine years of CDC data, and parameter distributions, we developed a Markov cohort model that included probabilistic sensitivity analysis. Cost, quality adjusted life-years (QALYs), and net monetary benefits are presented for each timing strategy. RESULTS: The beginning of December is the optimal time for HIV+ patients to receive the seasonal influenza vaccine. Assuming a willingness-to-pay threshold of $50,000, the net monetary benefit associated with a Dec 1 vaccination date is $19,501.49 and the annual QALY was 0.833744. INTERPRETATION: Our results support a policy of administering the seasonal influenza vaccination for this population in the middle of November or beginning of December, assuming nothing is know about the upcoming flu season. But because the difference in between this strategy and the CDC guideline is small-12 deaths averted per year and a savings of $60 million across the HIV+ population in the US-more research is needed concerning strategies for subpopulations.

Factors associated with pretreatment and treatment dropouts: comparisons between Aboriginal and non-Aboriginal clients admitted to medical withdrawal management.

BACKGROUND: Addiction treatment faces high pretreatment and treatment dropout rates, especially among Aboriginals. In this study we examined characteristic differences between Aboriginal and non-Aboriginal clients accessing an inpatient medical withdrawal management program, and identified risk factors associated with the probabilities of pretreatment and treatment dropouts, respectively. METHODS: 2231 unique clients (Aboriginal = 451; 20%) referred to Vancouver Detox over a two-year period were assessed. For both Aboriginal and non-Aboriginal groups, multivariate logistic regression analyses were conducted with pretreatment dropout and treatment dropout as dependent variables, respectively. RESULTS: Aboriginal clients had higher pretreatment and treatment dropout rates compared to non-Aboriginal clients (41.0% vs. 32.7% and 25.9% vs. 20.0%, respectively). For Aboriginal people, no fixed address (NFA) was the only predictor of pretreatment dropout. For treatment dropout, significant predictors were: being female, having HCV infection, and being discharged on welfare check issue days or weekends. For non-Aboriginal clients, being male, NFA, alcohol as a preferred substance, and being on methadone maintenance treatment (MMT) at referral were associated with pretreatment dropout. Significant risk factors for treatment dropout were: being younger, having a preferred substance other than alcohol, having opiates as a preferred substance, and being discharged on weekends. CONCLUSIONS: Our results highlight the importance of social factors for the Aboriginal population compared to substance-specific factors for the non-Aboriginal population. These findings should help clinicians and decision-makers to recognize the importance of social supports especially housing and initiate appropriate services to improve treatment intake and subsequent retention, physical and mental health outcomes and the cost-effectiveness of treatment.

Cost-effectiveness of newer antiretroviral drugs in treatment-experienced patients with multidrug-resistant HIV disease.

OBJECTIVE: Newer antiretroviral drugs provide substantial benefits but are expensive. The cost-effectiveness of using antiretroviral drugs in combination for patients with multidrug-resistant HIV disease was determined. DESIGN: A cohort state-transition model was built representing treatment-experienced patients with low CD4 counts, high viral load levels, and multidrug-resistant virus. The effectiveness of newer drugs (those approved in 2005 or later) was estimated from published randomized trials. Other parameters were estimated from a randomized trial and from the literature. The model had a lifetime time horizon and used the perspective of an ideal insurer in the United States. The interventions were combination antiretroviral therapy, consisting of 2 newer drugs and 1 conventional drug, compared with 3 conventional drugs. Outcome measures were life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness. RESULTS: Substituting newer antiretroviral drugs increased expected survival by 3.9 years in advanced HIV disease. The incremental cost-effectiveness ratio of newer, compared with conventional, antiretroviral drugs was $75,556/QALY gained. Sensitivity analyses showed that substituting only one newer antiretroviral drug cost $54,559 to $68,732/QALY, depending on assumptions about efficacy. Substituting 3 newer drugs cost $105,956 to $117,477/QALY. Cost-effectiveness ratios were higher if conventional drugs were not discontinued. CONCLUSIONS: In treatment-experienced patients with advanced HIV disease, use of newer antiretroviral agents can be cost-effective, given a cost-effectiveness threshold in the range of $50,000 to $75,000 per QALY gained. Newer antiretroviral agents should be used in carefully selected patients for whom less expensive options are clearly inferior.

The cost-effectiveness and value of information of three influenza vaccination dosing strategies for individuals with human immunodeficiency virus.

BACKGROUND: Influenza vaccine immunogenicity is diminished in patients living with HIV/AIDS. We evaluated the cost-effectiveness and expected value of perfect information (EVPI) of three alternative influenza vaccine dosing strategies intended to increase immunogenicity in those patients. METHODS: A randomized, multi-centered, controlled, vaccine trial was conducted at 12 CIHR Canadian HIV Trials Network sites. Three dosing strategies with seasonal, inactivated trivalent, non-adjuvanted intramuscular vaccine were used in HIV infected adults: two standard doses over 28 days (Strategy A), two double doses over 28 days (Strategy B) and a single standard dose of influenza vaccine (Strategy C), administered prior to the 2008 influenza season. The comparator in our analysis was practice in the previous year, in which 82.8% of HIV/AIDS received standard-dose vaccination (Strategy D). A Markov cohort model was developed to estimate the monthly probability of Influenza-like Illness (ILI) over one influenza season. Costs and quality-adjusted life years, extrapolated to the lifetime of the hypothetical study cohorts, were estimated in calculating incremental cost-effectiveness ratios (ICER) and EVPI in conducting further research. RESULTS: 298 patients with median CD4 of 470 cells/µl and 76% with viral load suppression were randomized. Strategy C was the most cost-effective strategy for the overall trial population and for suppressed and unsuppressed individuals. Mean ICERs for Strategy A for unsuppressed patients could also be considered cost-effective. The level of uncertainty regarding the decision to implement strategy A versus C for unsuppressed individuals was high. The maximum acceptable cost of reducing decision uncertainty in implementing strategy A for individuals with unsuppressed pVL was $418,000--below the cost of conducting a larger-scale trial. CONCLUSION: Our results do not support a policy to implement increased antigen dose or booster dosing strategies with seasonal, inactivated trivalent, non-adjuvanted intramuscular vaccine for individuals with HIV in Canada. TRIAL REGISTRATION: ClinicalTrials.gov NCT00764998.

Health related quality of life trajectories of patients in opioid substitution treatment.

BACKGROUND: While opioid substitution treatment (OST) provides the opportunity for substantial improvements in health related quality of life (HRQoL), this relationship is seldom documented and poorly understood. Our objectives were to identify differences in trajectories of HRQoL among chronic opioid-dependent patients and factors associated with improvement and deterioration in HRQoL following enrolment in opioid substitution treatment. METHODS: In the North American Opiate Medication Initiative (NAOMI) randomized controlled trial, the Euroqol (EQ-5D) and other measures of demographic, health and drug use characteristics were collected at baseline and quarterly follow-up. Latent class growth analysis was applied to identify classes of HRQoL trajectories during treatment, while baseline correlates of class membership and factors associated with changes in HRQoL were identified in multivariate analyses. RESULTS: Three classes of individual HRQoL growth trajectories were identified: class 1: low and constant (19.5%), class 2: moderate and improved (61.2%), and class 3: high and constant (19.3%). Class 1 members were younger and more likely to be female, while class 3 members were less likely to have chronic conditions and had lower illicit drug use severity at baseline. Changes in HRQoL were associated with improvements in housing status (positive), medical events (negative) and decreases in illicit drug use (positive). CONCLUSIONS: Insight into the extent of HRQoL response and characteristics of patients responding to treatment can be used to design interventions that maximize HRQoL improvement. Given its role in economic evaluation and subsequent resource allocation decisions, HRQoL should be considered an endpoint in treatment evaluations for opioid dependence.

The concurrent validity and responsiveness of the health utilities index (HUI 3) among patients with advanced HIV/AIDS.

OBJECTIVES: To assess the concurrent validity and responsiveness of the Health Utility Index 3 (HUI3) in patients with advanced HIV/AIDS, and to determine the responsiveness of this measure, the MOS-HIV and EQ-5D to HIV-related clinical events. METHODS: Data from the OPTIMA (OPTions In Management with Antiretrovirals) trial was analyzed. Two aspects of the validity of the HUI3 were considered: concurrent validity was evaluated using Spearman correlations with MOS-HIV component and summary scores. Responsiveness to AIDS-defining events (ADE) and all adverse events (our external change criterion) was assessed using area under the receiver operating characteristic (AUROC) curves. RESULTS: The study enrolled 368 patients (mean follow-up: 3.66 years); 82% had at least one severe adverse event and 27% had at least one ADE. The HUI3 scale and items showed good concurrent validity, with 85% of the expected relationships with the MOS-HIV subscales verified. The HUI3 was responsive to both adverse events (AUROC [95%CI]: 0.68 [0.57, 0.80]) and ADEs (0.62 [0.51, 0.74]). The EQ-5D was responsive to ADEs (0.66 [0.56, 0.76]), but not responsive to adverse events (0.56 [0.46, 0.68]). CONCLUSION: The HUI3 is a valid and responsive measure of the change in HRQoL associated with clinical events in an advanced HIV/AIDS population.

Value of information of a clinical prediction rule: informing the efficient use of healthcare and health research resources.

OBJECTIVES: The aim of this study was to estimate the potential cost-effectiveness and expected value of perfect information of a recently derived clinical prediction rule for patients presenting to emergency departments with chest discomfort. METHODS: A decision analytic model was constructed to compare the Early Disposition Prediction Rule (EDPR) with the current standard of care. Results were used to calculate the potential cost-effectiveness of the EDPR, as well as the Value of Information in conducting further research. Study subjects were adults presenting with chest discomfort to two urban emergency departments in Vancouver, British Columbia, Canada. The clinical prediction rule identifies patients who are eligible for early discharge within 3 hours of presentation to the emergency department. The outcome measure used was inappropriate emergency department discharge of patients with acute coronary syndrome (ACS). RESULTS: The incremental cost-effectiveness ratio of the EDPR in comparison to usual care was (negative) $2,999 per inappropriate ACS discharge prevented, indicating a potential cost-savings in introducing the intervention. The expected value of perfect information was $16.3 million in the first year of implementation, suggesting a high benefit from conducting further research to validate the decision rule. CONCLUSIONS: The EDPR is likely to be cost-effective; however, given the high degree of uncertainty in the estimates of costs and patient outcomes, further research is required to inform the decision to implement the intervention. The potential health and monetary benefits of this clinical prediction rule outweigh the costs of doing further research.

Medical withdrawal management in Vancouver: service description and evaluation.

This study evaluates a medically managed inpatient detoxification service (Vancouver Detox (VD)) and investigates its clients' characteristics over a 1-year period. We present information on the daily operation at VD, and examine accessibility and efficiency of it from five perspectives: wait time, pretreatment attrition rate, treatment completion rate, length of stay (LOS), and occupancy rate (OR). In addition, we explore the impacts of seasonality and the monthly welfare check on the utilization of the service. Among 2294 referrals, 35% dropped out without engaging in treatment. Among those who were admitted to VD, 78% completed the treatment program. Shorter wait time and lower OR were found during the welfare check issuance period, and lower OR was found during summer. In addition, the patterns of utilization of VD were changed over the welfare check issuance period. Our analysis indicates that operational accessibility and efficiency at VD could be improved by specifically addressing these factors.