Pulmonology · Medical Literature
A Pilot Economic Evaluation of a Nature-Based Therapy for Chronic Obstructive Pulmonary Disease in Austria.
Abstract
This study presents a pilot cost-benefit analysis of a nature-based therapy (NBT) for Chronic Obstructive Pulmonary Disease (COPD) in Austria. Within the framework of a randomised controlled trial, we identify cost categories, quantify the costs and benefits, and synthesise findings through a partial economic evaluation. Costs were estimated for two scenarios: the trial setting and a hypothetical roll out. Benefits were valued using contingent valuation to estimate willingness to pay (WTP). The trial scenario costs were €326.27 per patient per day, while the roll out scenario estimated was €171.84 per patient per day. Cost component analysis revealed accommodation and staff as the highest contributors in both scenarios. Marginal WTP was estimated at between €25-€35 per day, indicating patients' perceived added value of NBT over standard clinic-based rehabilitation. These exploratory findings suggest NBT could be financially viable if marginal costs are lower than the estimated WTP. This study provides important preliminary evidence on the economic aspects of NBT, highlighting its potential as a sustainable alternative to standard COPD therapy. We recommend that future research expand upon our initial findings and incorporate economic assessments from the early trial design stage to enable more comprehensive cost-benefit analyses, thus facilitating informed decision-making on the implementation of such programmes.
Clinical relevance
In patients with COPD, what are the estimated costs and patient-perceived monetary benefits of a nature-based therapy (NBT) rehabilitation programme, and is such a programme potentially financially viable compared to standard clinic-based rehabilitation? __SNAPSHOT__ {"studyDesign":"Pilot partial economic evaluation (cost-benefit analysis with contingent valuation) nested within a randomised controlled trial","setting":"Salzburg, Austria; Krimml Waterfalls site; academic/clinical trial setting","sampleSize":"Overall RCT: n=99 randomised across three arms; economic/WTP subsample: n=30 (participants from green exercise and waterfall intervention arms of one trial wave)","population":"Adults with COPD enrolled in an RCT-based outdoor nature rehabilitation programme in Austria; specific COPD severity staging (GOLD classification), age range, comorbidities, and spirometric data not reported in the abstract","intervention":"14-day nature-based therapy (NBT) comprising outdoor walking, mobilisation and deflation exercises, relaxation exercises, strength training, and extended nature walks; the waterfall subgroup additionally received Krimml Waterfall aerosol inhalation during activities","comparator":"Control group (no NBT intervention; general COPD health advice only) within the RCT; cost comparisons made between trial-setting and hypothetical programme roll-out scenarios rather than head-to-head clinical outcomes vs. control","primaryOutcome":"Cost per patient per day (trial scenario vs. hypothetical roll-out scenario); marginal willingness to pay (WTP) per patient per day for NBT over standard clinic-based rehabilitation, estimated via contingent valuation","followUp":"14 days (duration of the rehabilitation programme); longer-term clinical and economic follow-up not reported","fundingSource":"Not reported"}
Key findings
In the trial scenario, the estimated cost of NBT was €326.27 per patient per day. Under a hypothetical programmatic roll-out scenario—intended to reflect more realistic operational efficiencies—the estimated cost fell to €171.84 per patient per day. Cost component analysis identified accommodation and staff as the largest contributors to total cost in both scenarios. Benefits were measured using contingent valuation: marginal willingness to pay (WTP) was estimated at €25–€35 per patient per day, representing patients' self-reported perceived added value of NBT over standard clinic-based rehabilitation. No formal incremental cost-effectiveness ratio (ICER), net present value, or cost-per-QALY was calculated. No clinical outcome data (e.g., FEV₁, 6-minute walk test, exacerbation rates, quality-adjusted life years) were reported in the economic abstract. Adverse events were not reported. Statistical significance of WTP estimates (confidence intervals, p-values) was not reported. The gap between total programme cost (€171.84–€326.27/day) and marginal WTP (€25–€35/day) is large; the authors note viability requires that only the marginal cost increment over standard rehabilitation—not total cost—be compared to WTP, though this marginal cost differential was not explicitly quantified.
Practice implications
This study establishes preliminary cost data and patient-perceived monetary value for a 14-day outdoor NBT programme for COPD in Austria, representing a novel and methodologically important first step. It does NOT establish clinical superiority of NBT over standard rehabilitation, does not report health outcomes, and does not demonstrate cost-effectiveness or cost-utility. The WTP methodology captures patient-perceived value but does not reflect payer willingness to pay, system-level cost offsets, or downstream healthcare utilisation savings. The marginal cost framing is conceptually sound but the actual marginal cost vs. standard rehabilitation was not quantified, making the viability inference contingent on unstated assumptions. The WTP subsample (n=30, intervention arms only) is very small and subject to selection bias and hypothetical bias inherent to contingent valuation. Generalisability beyond Austrian COPD patients in an alpine/waterfall setting is uncertain. The findings are hypothesis-generating only. Only the abstract was available for this review, which is a significant limitation to full methodological appraisal. __LIMITATIONS__ Pilot study with a very small WTP subsample (n=30 from intervention arms only); underpowered for robust economic inference,Partial economic evaluation only—no cost-effectiveness, cost-utility, or full cost-benefit analysis completed; no QALY or clinical outcome data linked to costs,Contingent valuation (stated preference/WTP) is prone to hypothetical bias, strategic bias, and anchoring; WTP may overestimate real willingness to pay,WTP subsample excluded the control arm, introducing selection bias and preventing comparison with non-intervention participants,Marginal cost of NBT over standard rehabilitation was not directly quantified, making the central financial viability conclusion speculative,14-day follow-up captures only immediate programme costs; long-term economic consequences (exacerbations, hospitalisations, quality of life) not assessed,No clinical outcomes reported; economic evaluation divorced from health benefit quantification,Roll-out cost scenario is hypothetical and based on assumed efficiencies not validated in practice,Funding source not reported; potential conflicts of interest cannot be assessed,Single geographic/ecological setting (Krimml Waterfalls, Salzburg) limits generalisability to other healthcare systems, climates, and COPD populations,Only abstract available for review; full methodological details including costing sources, sensitivity analyses, and statistical reporting could not be evaluated __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This pilot economic analysis provides preliminary and exploratory cost data for a 14-day nature-based COPD rehabilitation programme in Austria, estimating delivery costs of €171.84–€326.27 per patient per day against a patient-perceived marginal WTP of €25–€35 per day. The study does not demonstrate clinical effectiveness, cost-effectiveness, or payer-level value; the financial viability inference rests on an unquantified marginal cost differential that requires prospective validation. Routine clinical adoption of NBT for COPD is not supported by these findings; confirmatory studies integrating clinical outcomes, full economic evaluation, and longer follow-up are needed before practice-level recommendations can be made.