Spread of wrong information can be a serious deterrent to information system use especially in case of online community which typically have thousands of end users. However, literature has been weak in linking the prevalence of health misinformation on online social networks to the factors contributing to misinformation. This study seeks to reduce this gap by examining the impact of thread characteristics and user characteristics on the extent of misinformation in online social networking forum related to Parkinson's disease. Our findings show that the correctness of a post is affected by clarity of the thread question, information richness and the user potential for making useful contributions.