Figure 1.

Literature review results summary.

Notes: The availability of literature is limited, as shown by the few results after multiple database searches. Many of the sputum storage articles do not pertain to this review’s selected organisms and disease areas. Furthermore the storage times are significantly shorter than required for a sputum library. Similarly, artificial sputum results often analyzed organisms not detailed in this review, and the severe lack of comparison data further complicated the selection process.

Abbreviations: ABSTR, abstract; KEY, keywords.