Nayak S, Greenspan SL, et al. - After 3 years of zoledronic acid treatment, taking 3-year holidays before restarting another treatment cycle for postmenopausal women with osteoporosis and femoral neck BMD T-scores between − 2.5 and − 3.5 is likely to be more cost-effective over the lifetime than cycles of 6 years of treatment prior to 3-year holidays.

• The authors created an individual-level state-transition microsimulation cost-effectiveness model to compare treatment strategies for women with osteoporosis over the lifetime of recurrent periods of 3 years of zoledronic acid followed by 3-year holidays (zoledronic acid 3/3), recurrent periods of 6 years of zoledronic acid followed by 3-year holidays (zoledronic acid 6/3), and no zoledronic acid treatment and femoral neck BMD T-scores between − 2.5 and − 3.5.

• For every therapy initiation age tested (50, 60, 70, and 80), base-case analysis and all key parameter sensitivity analysis findings revealed that zoledronic acid 3/3 was consistently the most cost-effective option, assuming a willingness-to-pay of $100,000 per quality-adjusted life-year (QALY).

• In general, the zoledronic acid 3/3 and 6/3 strategies were pretty equal in terms of lifetime efficacy (QALYs); however, lifetime direct health care costs were roughly $2000 cheaper for the 3/3 strategy.

• The zoledronic acid 3/3 approach was chosen in more than 70% of the iterations for a willingness-to-pay threshold of $100,000/QALY for all treatment initiation ages assessed, according to the results of a probabilistic sensitivity analysis.