Employers have had some success in controlling rising health care costs, but they have done so mainly by shifting costs to employees through high-deductible health care plans. Commonwealth Fund authors note in the Harvard Business Review that employers can better face the challenge of high costs by joining together to form purchasing alliances.
The paper can be obtained at https://hbr.org/2018/11/to-control-health-care-costs-u-s-employers-should-form-purchasing-alliances.