“…In order to assess the diagnostic capacity of a biomarker, it is necessary to design a diagnostic precision study that reveals discrimination and classification measures of a clinical condition (McInnes, Moher, Thombs, McGrath, & Bossuyt, 2018). Although IL1β was the first cytokine to be quantified in the gingival tissue of patients with chronic periodontitis (Hönig, Rordorf Adam, Siegmund, Wiedemann, & Erard, 1989), very few studies have been published on its diagnostic accuracy in saliva, and none of them have evaluated the impact of a patient's “smoking habit” on this diagnostic capability (Afacan, Öztürk, Emingil, Kose, & Bostanci, 2018; Ebersole, Nagarajan, Akers, & Miller, 2015; Ebersole et al, 2013; Isaza‐Guzmán, Medina‐Piedrahíta, Gutiérrez‐Henao, & Tobón‐Arroyave, 2017; Ramseier et al, 2009; Sánchez, Miozza, Delgado, & Busch, 2013; Wu et al, 2018).…”