Objective:
     
     To review the effects of shared decision making (SDM) on health outcomes, health care quality, cost, and consultation time METHODS: We conducted an umbrella review and searched systematic reviews on SDM from PubMed, CINHAL, and Web of Science. We included reviews on SDM interventions used in a health care setting with patients. We assessed the eligibility of retrieved articles and evaluated whether the review addressed Consolidated Framework for Implementation Research (CFIR) characteristics.
   

Results:
     
     Out of 3678 records, 48 reviews were included. Half of the reviews focused exclusively on RCT studies (n = 21). A little less than half were focused specifically on decision aids (n = 23). Thirty-two reviews discussed CFIR characteristics explicitly or implicitly; the majority of which were specific to intervention characteristics. Reviews tended to cluster around patient populations and tended to be low or critically low to moderate in their quality. Reviews of SDM on health outcomes, health care quality, cost, and consultation time were highly uncertain but often ranged from neutral to positive.
   

Conclusions:
     
     We observed that SDM implementation did not typically increase costs or increase consultation time while having some neutral to positive benefits on outcomes and quality for certain populations. Gaps in knowledge remain including better research on the climate where SDM is most effective.