Fig 1.

Proportion of positive microscopy slides (black line) pre- implementation of quality control measures, during implementation and post-implementation (limited to the first respiratory sample of each patient). Culture positivity for samples included in smear analysis are shown (blue line). Samples were comparable across different time periods. (DOI10.6084/m9.figshare.9882935) Pre-implementation: smears were stained using a staining automate and the Kinyoun staining method. Implementation: Fluorescence microscopy was introduced accompanied by using frosted slides and water filters. SOPs were developed including e.g. documentation of batch controls of staining solution, training of technicians and introduction of positive and negative smear controls. Post-implementation: Quality control measures were continued and technicians were re-trained at 6 monthly intervals.