The cost-effectiveness analysis of drug therapy versus surgery for symptomatic adenoid hypertrophy by a Markov model

Abstract

Purpose: Adenoid hypertrophy (AH) is common among young children. Adenoid-based surgery and drug therapy could be applied for symptomatic AH patients, yet the treatment decision is difficult to make due to the diverse cost and efficacy between these two treatments.

Methods: A Markov simulation model was designed to estimate the cost-effectiveness (CE) of the adenoid-based surgery and the drug therapy for symptomatic AH patients. Transition probabilities, costs and utilities were extracted from early researches and expert opinions. Simulations using two set of parameter inputs for China and the USA were performed. Primary outcome was cost per QALY gained over a 6-year period. Deterministic and probabilistic sensitivity analyses were also conducted.

Results: The utility for the surgery group and the drug group were 4.10 quality-adjusted life years (QALYs) and 3.58 QALYs, respectively. The cost of the surgery group was more than that of the drug group using model parameters specific to China ($1069.0 vs. $753.7) but was less for the USA ($1994.4 vs. $3977.7). Surgery was dominant over drug therapy when US specific parameters were used. Surgery group had an ICER of $604.0 per QALY when parameters specific to China was used.

Conclusion: Surgery is cost-effective in the simulations for both China and the USA at WTP thresholds of $9633.1 and $62,517.5, respectively.

Keywords: Adenoid hypertrophy; Adenoid surgery; Cost-effectiveness analysis; Markov model.

Fig. 1

Flow diagram of the Markov cohort model. Two groups were divided as the drug group and the surgery group. Straight lines with arrows between the panes represent the process of patients’ health condition during the treatments

Fig. 2

The tornado diagrams for China. The tornado diagrams are sensitivity analyses including all the parameters set in the model for the surgery group (a) and the drug group (b), respectively. The longer the bar is, the more influence the parameter has on the cost-effectiveness of the certain group. Abbreviations: health utility of a symptomatic state (Eff_Sym), health utility of asymptomatic patients in surgery group (Eff_Sur), health utility of asymptomatic patients in the drug group (Eff_Drug), cost of the surgery (Cost_Surg), cost of the surgical complications (Cost_Comp), cost of a 3-month drug therapy (Cost_Drug), the rate of surgery complications (Sur_Comp), the effective rate of the surgery (Sur_Asym), the ineffective rate of the drug therapy (Dru_Asym), the recurrence rate after surgery (Sur_RE), the recurrence rate after drug therapy (Dru_RE)

Fig. 3

The tornado diagrams for the USA. The tornado diagrams are sensitivity analyses including all the parameters set in the model for the surgery group (a) and the drug group (b), respectively. The longer the bar is, the more influence the parameter has on the cost-effectiveness of the certain group. Abbreviations: health utility of a symptomatic state (Eff_Sym), health utility of asymptomatic patients in surgery group (Eff_Sur), health utility of asymptomatic patients in the drug group (Eff_Drug), cost of the surgery (Cost_Surg), cost of the surgical complications (Cost_Comp), cost of a 3-month drug therapy (Cost_Drug), the rate of surgery complications (Sur_Comp), the effective rate of the surgery (Sur_Asym), the ineffective rate of the drug therapy (Dru_Asym), the recurrence rate after surgery (Sur_RE), the recurrence rate after drug therapy (Dru_RE)

Fig. 4

One-way sensitivity analysis of health utility of a symptomatic state. One-way sensitivity analysis of health utility of a symptomatic state for China (a) and the USA (b). The line above represents a better cost-effectiveness. Abbreviations: health utility of a symptomatic state (Eff_Sym)

Fig. 5

The cost-effectiveness acceptability curve of the two strategies. The cost-effectiveness acceptability curve for China (a) and the USA (b). The curve on the upside indicates a better cost-effective outcome for the population with a certain willingness-to-pay (WTP)