You may have missed Lahey Health's plan to acquire Winchester Hospital in the current swirl of Massachusetts hospital deals. But it caught the attention of the state's Health Policy Commission, which has the authority to review, but not stop, ownership changes that may increase health care costs. The commission is supposed to make sure health care spending does not grow faster than the cost of other goods and services. Commission staff told Lahey late Friday that they would conduct a full cost and market impact review of the Winchester deal.