complete_unique affect ameliorate associated benefit better causal complicate cost_effective deteriorate difference effect evidence expected greater impose improve increase induce inflict lead lower maintain more more_frequently need no_ideal onset open_issue optimize produce promising reason reduce related result_in risk risk_factor successful superior achieve adequate adverse_effect aid appropriate assist comparable consequence contribute decrease determinant develop due_to efficacy efficient elicit enhance exacerbate fewer gain help higher impact link make_difficult overcome persist pose predictor prevent promote raise safety select_over similar stem support because concerning helpful inconclusive inferior significant slow