مقرون به صرفه بودن از نظارت ورزش درمانی در بیماران مبتلا به نارسایی قلب

Objective Exercise therapy in heart failure (HF) patients is considered safe and has demonstrated modest reduction in hospitalization rates and death in recent trials. Previous cost-effectiveness analysis described favorable results considering long-term supervised exercise intervention and significant effectiveness of exercise therapy; however, these evidences are now no longer supported. To evaluate the cost-effectiveness of supervised exercise therapy in HF patients under the perspective of the Brazilian Public Healthcare System. Methods We developed a Markov model to evaluate the incremental cost-effectiveness ratio of supervised exercise therapy compared to standard treatment in patients with New York Heart Association HF class II and III. Effectiveness was evaluated in quality-adjusted life years in a 10-year time horizon. We searched PUBMED for published clinical trials to estimate effectiveness, mortality, hospitalization, and utilities data. Treatment costs were obtained from published cohort updated to 2008 values. Exercise therapy intervention costs were obtained from a rehabilitation center. Model robustness was assessed through Monte Carlo simulation and sensitivity analysis. Cost were expressed as international dollars, applying the purchasing-power-parity conversion rate. Results Exercise therapy showed small reduction in hospitalization and mortality at a low cost, an incremental cost-effectiveness ratio of Int$26,462/quality-adjusted life year. Results were more sensitive to exercise therapy costs, standard treatment total costs, exercise therapy effectiveness, and medications costs. Considering a willingness-to-pay of Int$27,500, 55% of the trials fell below this value in the Monte Carlo simulation. Conclusions In a Brazilian scenario, exercise therapy shows reasonable cost-effectiveness ratio, despite current evidence of limited benefit of this intervention.

Heart failure (HF) is a common health care problem worldwide, with elevated costs associated to its treatment [1]. During the past 20 years several effective therapies have changed HF management and clinical outcomes and these have been formally evaluated through economic analyses [2], [3] and [4]. The decrease in HF mortality was followed by an increase in its prevalence, with direct effect on health care budgets resulting from the rising number of hospitalizations and therapeutic procedures [5]. HF is a complex syndrome characterized by reduced exercise tolerance and the involvement of multiple physiopathologic mechanisms [6]. In the past patients were often advised to limit their efforts in daily activities; however, several studies suggest that exercise training may reduce mortality and morbidity in HF patients [7] and [8]. These studies also demonstrated that exercise training could be performed safely in appropriately evaluated cases of patients who present in clinically compensated New York Heart Association (NYHA) functional class II and III, as endorsed by current guidelines [9] and [10]. For health care managers, the decision to incorporate exercise therapy in treatment of patients with HF should be based in several perspectives, including cost-effectiveness studies of the intervention. In 2001, Georgiou et al. [11] published a cost-effectiveness analysis of supervised exercise intervention in HF patients showing a very favorable cost-effectiveness ratio of $1773 per life-year saved, considering a 14-month period of supervised exercise intervention in a time horizon of 10 years applied to a North-American setting. Recently a multicenter randomized controlled trial of 2331 HF outpatients [12] described an exercise-based intervention being compared with standard treatment. After 2.5 years of follow-up, including a short training period in a facility followed by home-based exercise sessions, a benefit was observed only after adjustment for other prognostic predictors of the primary endpoint. The authors concluded that exercise training is a safe intervention associated with a modest reduction in hospitalization and mortality, far from the assumed estimations in previous cost-effectiveness analysis [12]. In this study we evaluated the economic impact of a supervised exercise intervention in a hypothetic stable outpatient HF cohort, considering current evidence of effectiveness and costs, offering health care professionals an updated assessment on the role of exercise in the management of HF.

The results of this model show that exercise therapy in HF patients has a modest but favorable incremental cost-effectiveness ratio of Int$26,462 per QALY and Int$21,169 per life-year in a Brazilian PHS scenario. The results were consistent considering sensitivity analyses performed and assumptions described. Our results show that this intervention has a reasonable cost-effectiveness ratio when compared to other incoming therapies, such as implantable cardioverter defibrillator devices [30], but closer to proposed willingness-to-pay for Brazil, as demonstrated in the acceptability curve. The ICER of this intervention is also higher than the estimated Brazilian hemodialysis cost per life-year gained (US$10,065) [31]. During the past three decades the exercise training approach concerning HF patients moved from absolute restraint to enthusiastically prescribed, based on a growing body of evidence suggesting physiologic and clinical benefit from exercise. Randomized controlled trials showed significant reductions in the composite endpoint of hospitalization and mortality in HF patients submitted to supervised sessions of exercise interventions, reaching almost 50% in one report [7], and averaging a 35% reduction in mortality and 28% in hospitalization rates in a meta-analysis published in 2004 [8]. Nonetheless, a recently published trial failed to prove superiority of an exercise therapy intervention in a multicenter-based strategy [12]. The HF-Action trial [12] was designed to test the hypothesis that exercise training prescribed to HF patients would reduce mortality, and although overall intention-to-treat results were of small magnitude, protocol-driven results and those adjusted for prognostic variables indeed suggest some benefit on mortality beyond reduction of hospitalization and improvement on quality of life, functional capacity, and other markers of well-being [32] and [33]. The true effect of exercise on mortality in this population is a matter of debate, although exercise is still considered a key aspect in the management of HF [9] and [34]. Our model was sensitive to this parameter; assuming even a small effect of 4% reduction in mortality, modest reduction of combined risk of death or HF-related hospitalization, exercise would still have a favorable cost-effectiveness ratio. Unfortunately we do not have large Brazilian studies describing the actual result of such interventions. There are several short-term randomized studies evaluating the effect of exercise among Brazilian HF patients, mostly limited to physiologic parameters, functional class, or quality of life [35] and [36]. We could not identify studies that have evaluated hard clinical endpoints such as death or hospitalization. Indirect evidence from these studies; however, support the concept that the results obtained locally are similar to the ones described by other international research groups [35] and [36]. Based on these assumptions we believe our findings could be a reasonable estimate of the cost-effectiveness ratio for the Brazilian PHS scenario, although the effect of the health care system itself and cultural and socioeconomic characteristics on the main result might be unpredictable. In another published cost-effectiveness analysis [11], the impressive absolute reduction of 19% fewer hospitalizations in the exercise group compared to standard treatment group and additional survival of 1.82 years was the determinant factor in effectiveness estimation, with a cost-effectiveness ratio of $1773 per life-year saved. In our model, we considered a less pronounced increase in survival (0.13 years) produced by exercise intervention, reflecting a more realistic ICER taking into account current data. Prospective economic evaluation from HF-Action [33] demonstrated that along the trial the exercise training program was of little systematic benefit in terms of overall resource use, but individual data indicate that most estimates were consistent with a decrease in costs (89.9%) and an increase in QALYs (76.5%), and that most of the bootstrap replications were either associated with cost-saving result or with ICER below $50,000 per QALY. Usual exercise intervention in HF requires at least 12 weeks of training, because during a period of this length patients can receive adequate care and perceive functional improvement, increasing adherence to the intervention. In our model, we determined that the 36 sessions should be supplemented with additional weekly supervised sessions to reinforce compliance to the intervention in an attempt to reach the effectiveness demonstrated in clinical trials. Perhaps these additional costs could be counterbalanced with increased effectiveness, but we opted to consider a conservative strategy in light of current evidence. Assuming that including different professionals and activities in every program is proportional to increasing costs of the intervention, reducing the number of sessions in a facility center is a valuable attempt to reduce treatment costs and increase cost-effectiveness ratio. In the real world exercise therapy is not considered the core of the standard care for HF patients. Commonly HF patients are aged and have other diseases (e.g., osteoarticular limitations) that restrict their mobility; plus, successful exercise therapy demands motivation and both family and patient engagement time. In today's health care system model, which is based in hospital procedures, there are few examples of rehabilitation centers to promote significant changes in patients' habits and minimize usual risk factors associated with cardiovascular diseases, such as lack of exercise, tobacco use, inappropriate food ingestion, and depression. Despite all these points, there is evidence—including that produced in our study—that committed patients with cardiac disease who have access to facilities with trained professionals and appropriate equipment could benefit from exercise therapy with reasonable cost-effectiveness ratio [37]. Common to other interventions that also rely on human behavior, long-term adherence to exercise in patients with HF remains a challenge and requires additional research to determine strategies aimed at improving compliance, which might be associated with increased effectiveness. Areas of needed research include identifying the subgroups of patients who benefit the most from this intervention, as well as the determining the optimal intensity, duration, and frequency of exercise needed to maximize clinical benefits. Some limitations in our modeling should be mentioned. First, we established a constant effectiveness. In the real world a considerable number of patients oscillate their attendance in rehabilitation programs. Another limitation is that true cost of HF treatment could be higher than assumed costs, although we used primary data from a cohort of HF patients, with values updated to 2008. As we assumed a third-party payer (i.e., government) perspective, we did not considered patient or family displacement cost in regard to the rehabilitation facility; indirect cost associated with productivity losses were also not included, although HF in Brazil is a retirement cause insured by the PHS. The main caveat regarding the results of our study is the broad variance in exercise effectiveness, even though in two-way sensitivity analysis we found that every scenario with effectiveness greater than 5% (considering mortality reduction) the exercise intervention brought benefits to HF patients. Exercise therapy seems to be safe and should be considered in stable HF patients as part of treatment regardless of individual beliefs. Although effectiveness of exercise therapy in HF patients seems to be lower than initially expected, its cost-effectiveness ratio remains acceptable for health policy decision makers to incorporate this intervention in the care of patients with HF.