“…However, the volume of articles differed between chronic diseases: 59 articles (79.7 %) included oncology samples [19, 32–40, 42–47, 50–55, 57–63, 65–72, 74, 76–96]; 12 articles (16.2 %) included depression [32, 33, 41, 62, 64, 75, 83, 93, 97–100]; 10 articles (13.5 %) included diabetes [18, 32, 33, 64, 74, 75, 83, 101–103]; 10 articles (13.5 %) included ischaemic heart disease [18, 32, 33, 48, 56, 64, 74, 75, 83, 102]; 7 articles (9.5 %) included COPD [32, 33, 49, 56, 74, 75, 102]; 7 articles (9.5 %) included asthma [18, 32, 33, 64, 74, 75, 83]; 6 articles (8.1 %) included arthritis [32, 33, 73–75, 83]; and 3 articles (4.1 %) included osteoporosis [73–75]. A total of 12 studies (16.2 %) included more than one disease of interest [18, 32, 33, 56, 62, 64, 73–75, 83, 93, 102].…”