2 0 1 3 ▁review ▁found ▁that ▁sm oking ▁b ans ▁were ▁associated ▁with ▁" sign ific ant ▁reduction ▁in ▁ac ute ▁M I ▁[ my oc ard ial ▁inf ar ction ] ▁risk ", ▁but ▁noted ▁that ▁“ stud ies ▁with ▁smaller ▁population ▁in ▁the ▁United ▁States ▁usually ▁reported ▁larger ▁redu ctions , ▁while ▁larger ▁studies ▁reported ▁relatively ▁mod est ▁redu ctions .” ▁ ▁A ▁ 2 0 1 4 ▁system atic ▁review ▁and ▁meta - analysis ▁found ▁that ▁smoke - free ▁legisl ation ▁was ▁associated ▁with ▁approximately ▁ 1 0 % ▁redu ctions ▁in ▁pre term ▁birth s ▁and ▁hospital ▁attend ance ▁for ▁ast h ma , ▁but ▁not ▁with ▁a ▁decrease ▁in ▁low ▁birth ▁weight . ▁A ▁ 2 0 1 6 ▁C och rane ▁review ▁found ▁that ▁since ▁the ▁previous ▁version ▁of ▁that ▁review ▁was ▁published ▁in ▁ 2 0 1 0 , ▁the ▁evidence ▁that ▁sm oking ▁b ans ▁improved ▁health ▁out comes ▁had ▁become ▁more ▁robust , ▁especially ▁with ▁respect ▁to ▁ac ute ▁coron ary ▁synd rome ▁adm issions . ▁ ▁However , ▁other ▁studies ▁came ▁to ▁the ▁conclusion ▁that ▁sm oking ▁b ans ▁have ▁little ▁or ▁no ▁short - term ▁effect ▁on ▁my oc ard ial ▁inf ar ction ▁rates ▁and ▁other ▁dise ases . ▁A ▁ 2 0 1 0 ▁study ▁from ▁the ▁US ▁used ▁huge ▁nation ally ▁representative ▁databases ▁to ▁compare ▁sm oking - rest rict ed ▁areas ▁with ▁control ▁areas ▁and ▁found ▁no ▁associations ▁between ▁sm oking ▁b ans ▁and ▁short - term