Photo by Todd McNaught
An expensive and unproven surgical procedure for emphysema may be justified, but only for a limited group of patients, according to a recent cost-benefit analysis of lung-volume-reduction surgery (LVRS).
The study, led by Dr. Scott Ramsey of the Public Health Sciences Division, was part of an unprecedented tandem evaluation of the medical benefits and cost-effectiveness of a surgical procedure. The results from the clinical trial, together with the economic analysis, will inform Medicare's impending decision about whether to reinstate coverage for LVRS. Medicare suspended coverage in 1996 due to insufficient evidence for the procedure's benefit and concerns over high surgery-related mortality observed for patients who underwent the procedure.
Both studies, presented May 20 at the American Thoracic Society 99th International Conference in Seattle, appear in the May 22 edition of the New England Journal of Medicine.
The clinical trial found that about one-quarter of study patients benefited from the procedure. Those whose disease was confined to the upper lobes of the lung, with very poor exercise capacity prior to surgery, had improved survival, lung function and quality of life three years after surgery. Based on these outcomes, Ramsey and colleagues determined from mathematical projections that if the benefits to this subgroup were sustained for 10 or more years, the cost-effectiveness of the procedure would approach levels consistent with other treatments that are considered good value for their expenditure. However, he said, because the long-term prediction is based on a statistical model rather than actual patient follow-up, the results should be interpreted cautiously.
"Based on our 10-year predictions, I think it would be reasonable for Medicare to cover the procedure, but coverage should probably be restricted to the patients in the upper-lobe, poor-exercise subgroup because it is only these people who have the most to gain relative to the substantial risk of morbidity (adverse medical outcomes) and mortality due to surgery," said Ramsey, an economist and physician.
A substantial minority of patients in the study had poor outcomes that resulted in extended hospital stays, nursing-home admissions and significant additional costs on top of the $35,000 price tag for the surgery alone.
"If the surgery were performed on 250,000 patients, probably a low estimate of the number who could be eligible, the cost to Medicare in the first year would exceed $300 million," he said. "That's why we felt it was important to conduct a prospective cost-effectiveness analysis alongside the clinical trial."
Co-authors of the cost-effectiveness study included PHS colleagues Kristin Berry and Dr. Ruth Etzioni; Drs. Sean Sullivan and Douglas Wood at the University of Washington; and Dr. Robert Kaplan at the University of California at San Diego.
The studies to evaluate LVRS for patients with severe emphysema began in 1996, as part of the National Emphysema Treatment Trial (NETT), a cooperative five-year effort between the National Heart, Lung, and Blood Institute and the Centers for Medicare & Medicaid Services. Medicare reimbursed costs for study participants.
Clinical trial results
To determine the effectiveness of LVRS, a clinical trial was conducted with 1,218 patients with severe emphysema. At the start of the study, all participants received six to 10 weeks of pulmonary rehabilitation, which included education, counseling, exercise training, and other techniques to help patients understand and manage their condition and optimize their ability to perform activities of daily living. The participants were then randomly divided into two groups: 608 patients were selected to receive surgery in addition to medical therapy and 610 continued receiving medical therapy only. Patients were followed for an average of 29 months.
Lung function and exercise capacity among surviving surgical patients generally improved significantly following LVRS, but after two years returned to about the same levels as before the procedure. In contrast, participants who received medical therapy alone on average deteriorated in their functional levels to below baseline. Although the overall mortality rate throughout the follow-up period was comparable between the two groups, the risk of death during the first 90 days was significantly higher for patients who underwent surgery compared to those who just received medical therapy (7.9 percent vs. 1.3 percent).
Outcomes varied among groups with different disease characteristics. A survival benefit was observed only for the approximately 25 percent of surgical patients whose disease was confined to the upper lobes of the lung and who had poor exercise capacity prior to treatment.
Ramsey's team assessed the costs - including expenses for surgery, additional medical care and hospital stays, medications, transportation expenses and time spent by caregivers - as well as quality of life as measured by patient surveys. Medical costs were based on Medicare reimbursements. In addition, the team tracked expense records provided by patients regarding their out-of-pocket costs for medication, travel and time spent seeking care.
"Basically, cost-effectiveness of a new technology is defined as what health value you get for what you spend compared to the next best treatment for the condition," Ramsey said.
"In the case of LVRS, we looked at costs for surgery and medical (nonsurgical) care and whether patients experience gains in survival, quality of life or both. We can compare the cost-benefit ratio to those for other surgeries, or more broadly, for anything we do in medicine."
The researchers found that in the first two years after surgery, medical costs were significantly higher for the surgery group due to the high price of surgery and the extreme expenses associated with treating adverse outcomes following the procedure. Total medical-care costs in the third year of follow-up were equivalent in both the LVRS and medical-therapy groups. Nonmedical costs such as transportation and time spent by unpaid caregivers (family and friends) were modest compared to medical costs and were similar overall for both groups. In part due to the high costs related to surgery, the cost-effectiveness of LVRS vs. medical therapy is less favorable than many surgical procedures three years after surgery. Using statistical modeling, the researchers also calculated cost-effectiveness at 10 years after treatment.
Economists express cost-effectiveness values for a medical procedure as a dollar amount per quality-adjusted year of life gained, a ratio calculated using medical expenses, survival data and quality-of-life factors. Lower ratios are preferred to higher ones.
Ramsey and colleagues found that three years after LVRS, the cost-effectiveness was $190,000 per quality-adjusted year of life gained. For the subgroup of patients who responded well to surgery, the cost-effectiveness of LVRS in year three was $98,000. A procedure is considered to be cost-effective if it has a value on the order of $50,000 per quality-adjusted year of life gained.
Based on their 10-year projections, the researchers calculated that the overall cost-effectiveness for the surgery would be $53,000 per quality-adjusted life-year gained and $21,000 for the subgroup that responded well to LVRS.
"I'm cautiously optimistic about the long-term cost-effectiveness of this procedure, particularly for the subgroup of patients who responded well to the surgery," he said.
"But because of the expense of conducting this type of clinical trial, this is the best data that will ever exist on this procedure. Future trials evaluating the favorable subgroup found in this trial are unlikely, and 10-year follow-up of the patients in this trial is unlikely. That makes it difficult to predict with confidence whether LVRS will be cost-effective over the long term."
Emphysema is a progressive, disabling and potentially deadly condition affecting approximately 2 million Americans, primarily seniors who are current or former cigarette smokers. The disease destroys the fine architecture of the lung, leading to large holes in the lung, obstruction of the airways, trapping of air and difficulty exchanging oxygen because of reduced elasticity of the lungs. Emphysema costs more than $2.5 billion in annual health-care expenses and causes about 17,000 deaths in the United States each year. There is no known cure for the disease.
LVRS attempts to restore the lung's ability to expand and contract by decreasing the size of the lungs, which become enlarged from inflammation in emphysema patients.