An assessment of nucleic acid amplification testing for active mycobacterial infection
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- Bu səhifədəki naviqasiya:
- Mortality
- Discussion
AFB = acid-fast bacilli; KPS = Karnofsky performance score, 0–100% = with 0% being dead, < 40% = unable to care for self and requires equivalent of institutional or hospital care, 50–70% = unable to work but able to live at home and care for most personal needs, = 80–90% able to carry on normal activity and to work, 100% = being normal with no signs of disease; NAAT = nucleic acid amplification testing; TB = tuberculosis; TBscore = score 0–13 based on the 13 clinical indications, each contributing 1 point, normal values are scored as zero a 87 (57%) of the AFB microscopy group vs 108 (64%) of 168 in the NAAT group were followed up within 2 weeks (p=0.170); of the patients who were not followed up within 2 weeks, 11 (17%) of 66 vs 6 (10%) of 60 had died (p=0.274), and 33 (50%) of 66 vs 36 (60%) of 60 were followed up > 2 weeks before/after the specified date (p=0.260). b 96 (56%) of 170 of the AFB microscopy group vs 88 (58%) of 151 in the NAAT group were followed up within 2 weeks (p=0.74); of the patients who were not followed up within 2 weeks, 15 (20%) of 74 vs 8 (13%) of 63 had died (p=0.237), and 22 (30%) of 74 vs 21 (33%) of 63 were followed up > 2 weeks before/after the specified date (p=0.651). c 81 (53%) of 153 of the AFB microscopy group vs 97 (58%) of 168 in the NAAT group were followed up within 2 weeks (p=0.39); of the patients who were not followed up within 2 weeks, 14 (19%) of 72 vs 14 (20%) of 71 had died (p=0.967), and 23 (32%) of 72 vs 23 (33%) of 71 were followed up > 2 weeks before/after the specified date (p=0.954). d 86 (51%) of 170 of the AFB microscopy group vs 71 (47%) of 151 in the NAAT group were followed up within 2 weeks (p=0.52); of the patients who were not followed up within 2 weeks, 21 (25%) of 84 vs 14 (18%) of 80 had died (p=0.241), and 28 (33%) of 84 vs 28 (35%) of 80 were followed up > 2 weeks before/after the specified date (p=0.822). Source: Theron et al. (2014) TBscores at baseline and at 2 months and 6 months follow-up were similar in both groups (Table ). When both tests were compared there were no differences reported in the median per-patient change in TBscore or KPS. The proportion of patients with a > 25% decrease in TBscore or KPS from recruitment to 2 and 6 months follow-up also did not differ.
Table Mortality after NAAT versus no NAAT
Comparator for Theron et al. (2014) was AFB microscopy Comparator for Yoon et al. (2012) was a historical control group DiscussionThere was little difference in the observed mortality and morbidity rates when the diagnosis of TB included the use of NAAT compared with no NAAT for patients in these two studies. The RCT showed a trend towards improved mortality rate with the use of NAAT at 2 months but this trend was not observed at 6 months. Both these studies were conducted in countries with a high prevalence of TB. The authors from both studies postulated various reasons for this general lack of effect on morbidity and/or mortality despite improved TB diagnosis and treatment initiation in the NAAT groups compared with the comparator groups. Theron et al. (2014) suggested that the potential long-term epidemiological effect of NAAT was probably underestimated in their study because of high levels of treatment initiation in AFB-negative patients in the comparator group. It should also be noted that while 112 NAAT-positive patients out of a total of 170 culture-positive (eventually treated) patients (66%) started treatment on the same day, the availability of same-day AFB microscopy results in the comparator group resulted in 67 AFB-positive patients out of 154 culture-positive (eventually treated) patients (44%) also starting treatment on the same day. This approximate 20% difference in treatment initiation between groups is unlikely to be reflected in treatment initiation rates in Australia because NAAT is suggested to be used as an adjunct to AFB testing. The incremental impact of NAAT over current testing practice in Australia, and the impact on patient morbidity and mortality, cannot be estimated from the study by Theron et al. (2014). Yoon et al. (2012) suggested that the lack of effect on 2-month mortality in their study may be due to several factors, including insufficient powering to detect small differences in mortality rates between groups, a significantly higher proportion of patients in the baseline phase receiving empiric TB treatment compared with the implementation phase, and more patients presenting with increased disease severity in the implementation phase than in the baseline phase. Thus, the authors concluded that the higher rates of empiric TB treatment in the baseline phase and sicker patients in the implementation phase may have attenuated the 2-month mortality in the implementation group. Due to the limited evidence provided by these two studies, a linked evidence approach was taken to inform this assessment. Yüklə 3,88 Mb. Dostları ilə paylaş:
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