Stages of smoking cessation among Malaysian adults: findings from National Health Morbidity Survey 2006 by Lim, Kuang Hock, Ibrahim, Normala, Mohd Ghazali, Sumarni, Kee, Chee Cheong, Lim, Kuang Kay, Chan, Ying Ying, Teh, Chien Huey, Tee, Eng Ong, Lai, Wai Yee, Nik Mohamed, Mohamad Haniki, Mohd Sidik, Sherina