Abstract:

Objective To explore the effect of improvement of the sputum sample quality on the positive detection rate of etiology in newly diagnosed pulmonary tuberculosis (PTB) patients through sputum retention interventions. Methods Five counties (districts) in Ganzhou, Jiangxi were selected as the research pilot areas. Using the method of community intervention trial, 771 newly diagnosed PTB patients diagnosed from March to July 2020 were selected as the control group, 645 newly diagnosed PTB patients from August to December 2020 were selected as the intervention group. In the control group, sputum samples were collected by the patients according to the doctor’s instructions, and intervention measures were implemented in the intervention group (medical staff instructed patients to collect sputum, and if patients had no sputum, heat-steam absorbing, climbing stairs or walking, patting back, or aerosol inhalation will be carried out to collect sputum samples). The difference of positive detection rate of etiology between the two groups were compared. The proportion and quality of 3 sputum specimens, including immediate sputum, morning sputum, and night sputum, collected in the intervention group, as well as the implementation of various sputum retention interventions were analyzed. Results The positive rate in the control group was 53.7% (414/771), which was significantly lower than that in the intervention group (64.3%, 415/645; χ²=16.396, P=0.000). The positive rates of sputum smear microscopy and GeneXpert MTB/RIF (“Xpert”) in the intervention group were 51.6% (316/612) and 62.4% (394/631) respectively, which were significantly higher than those in the control group (42.1%, (313/743) and 55.0% (396/720), respectively; χ ² values were 12.196 and 7.667, P values were 0.000 and 0.006, respectively). Among them, the positive rate of Xpert test of patients in the intervention group with negative sputum smear microscopy was 28.3% (93/329), which was significantly higher than that in the control group (20.3% (93/458); χ ²=4.114, P=0.043). The percentage of immediate sputum retention in the intervention group was 99.5% (642/645), and the qualified rate was 90.0% (578/642); the percentages of morning and night sputum retentions were 95.5% (616/645) and 88.7% (572/645), and the qualified rates were 88.1% (543/616) and 88.6% (507/572). In the intervention group, 77.1% (495/642) of the patients were directly retained sputum after doctors’ sputum retention education and nurses’ on-site guidance, 10.1% (65/642) through heat-steam absorbing, 4.7% (30/642) by climbing stairs, 4.7% (30/642) by patting backs, and 3.6% (23/642) by aerosol inhalation. Conclusion Improving the quality of sputum samples through sputum retention intervention could significantly increase the positive detection rate of etiology in newly diagnosed PTB patients. Medical staff should provide patients with appropriate sputum retention education and guidance on sputum retention.

Key words: Tuberculosis,pulmonary, Sputum, Quality control, Intervention studies