prevention is (always) better than cure

/pɹɪvˈɛnʃən ɪz ˈɔːlweɪz ɔː bˈɛtə ðɐn kjˈʊə/

/pɹɪvˈɛnʃən ɪz ˈɔːlweɪz ɔːɹ bˈɛɾɚ ðɐn kjˈʊɹ/

used to imply that it is more effective to take preventative measures to avoid problems or illnesses before they occur, rather than waiting to deal with them after they have already happened