Ng SK, et al. - Researchers investigated the impact of analytical methods on the patterns of multimorbid health conditions, using the Australian National Health Survey (NHS) 2007–08 data in a comparison analysis. For this systematic review, they identified 13,194 studies from PubMed and EMBASE from inception to January 2017 and excluded 13 091 based on titles/abstracts. A total of 41 studies using five different analytical methods to identify multimorbid conditions were identified. In the comparison analysis, they found that when the methods were applied to the same NHS data, variation was evident in identified groups of multimorbid conditions. They extracted main similarities among the groupings obtained by the five methods: cardiovascular and metabolic diseases, mental health problems and allergic diseases.