Figure 1).

Bland-Altman plots of mean differences versus mean values of total cell count (TCC) show the agreement between samples processed by the two different methods. A Total sputum cell counts from aliquots from the same sample processed by the routine and formaldehyde preservation methods. B Total sputum cell counts from aliquots from the same sample processed by the routine and alcohol preservation methods. The solid line represents the mean difference (see also Tables 1 and 2), the dotted lines indicate ±1.96 SDs from the mean (ie, 95% CIs)