Empirical evidence of delays in diagnosis and treatment of pulmonary tuberculosis: systematic review and meta-regression analysis.

BACKGROUND: Delays in diagnosis and treatment of pulmonary tuberculosis are a major set-back to global tuberculosis control. There is currently no global evidence on the average delays thus, the most important contributor to total delay is unknown. We aimed to estimate average delay measures and to investigate sources for heterogeneity among studies assessing delay measures. METHODS: Systematic review of studies reporting mean (± standard deviation) or median (interquartile range, IQR) of patient, doctor, diagnostic, treatment, health system and/or total delays in journal articles indexed in PubMed. We pooled mean delays using random-effects inverse variance meta-analysis, investigated for variations in pooled estimates in subgroup analyses and explored for sources of heterogeneity using pre-specified explanatory variables. RESULTS: The systematic review included 198 studies (831,724 patients) from 78 countries. The median number of patients per study was 243 (IQR; 160-458) patients. Overall, the pooled mean total delay was 87.6 (95% CI: 81.4-93.9) days. The most important and largest contributor to total delay was patient delay with a pooled mean delay of 81 (95% CI: 70-92) days followed by doctor's delay and treatment delay with pooled mean delays of 29.5 (95% CI: 25.9-33.0) and 7.9 (95% CI: 6.9-8.9) days respectively. There was considerable heterogeneity in all pooled analyses (I2 > 95%). In the meta-regression models of mean delays, studies excluding extra-pulmonary tuberculosis patients reported increased mean doctor's delay by 45 days on average, non-use of chest x-ray and conducting studies in high income countries decreased mean treatment delay by 20 and 22 days on average, respectively. CONCLUSION: Strategies to address patients' delay could have important implications for the success of the global tuberculosis control programmes.

A nanosilica-coated thread-based analytical device for nitrate and nitrite detection in food samples.

A new microfluidic thread-based analytical device (µTAD) for nitrate and nitrite determination in food samples was developed. The cotton thread substrate was coated with nanosilica to increase its hydrophilicity and stability, and polylactic acid was applied to one end of the nanosilica-coated thread to constrain the fluid flow along the thread in one direction. Quantification of nitrate and nitrite was based on the modified Griess reaction, using sulfanilamide and N-(1-naphthyl) ethylenediamine as chromogenic reagents, and utilizing a distance-based detection technique. Linear responses were observed in a range of 4-25 mg L-1 (R2 = 0.9991) for nitrite and a range of 8-50 mg L-1 (R2 = 0.9989) for nitrate. The limits of detection for nitrite and nitrate were 1.5 and 3.1 mg L-1, respectively. The detection time was 5 min for nitrite analysis, and 7 min for nitrate analysis. The new method demonstrated good precision, accuracy, selectivity, and stability. The performance of the proposed µTAD for nitrite and nitrate determination in real food samples was comparable to that of the conventional UV-Vis spectrophotometric method. The proposed µTAD could serve as a simple, low-cost, and portable method for nitrite and nitrate detection in food samples.

A highly sensitive hyperbranched Au plasmonic blackbody immunochromatographic assay for detection of leucomalachite green in fish and shrimp.

A novel immunochromatographic assay (ICA) based on hyperbranched Au plasmonic blackbodies (AuPBs) with a smartphone readout was fabricated for the detection of leucomalachite green (LMG) in fish and shrimp products. The ICA was carried out in a competitive immunoassay format with AuPBs as labels. The developed AuPBs-ICA allowed for the LMG detection with a low detection limit (0.15 µg L-1) within 5 min by the smartphone reader. With the label-AuPBs ICA, the color intensity response was linearly related to the concentrations of the LMG (0.2 -1.7 µg L-1). The test line signal could be clearly distinguished at a 1.7 µg L-1 LMG as a cut-off level by the naked eye, which is lower than the conventional colloidal gold nanoparticle (2 µg L-1) and star-shaped nanoparticles (1.9 µg L-1) labeling. LMG contamination in samples was determined with the proposed AuPBs-ICA and the enzyme-linked immunosorbent (ELISA). The AuPBs-ICA results showed good agreement with those from the ELISA. The proposed AuPBs-ICA has the potential to be used as a rapid, sensitive, and simple device for the analysis of LMG residues in fish and shrimp samples.

Is evidence-based medicine a mirage in resource-constrained settings? A survey among resident doctors in selected teaching hospitals in Nigeria.

AIM: The study aimed to assess the self-rated knowledge, attitude toward, and practice (KAP) of evidence-based medicine (EBM) among resident doctors in Nigeria. METHODS: This was a cross-sectional web-based survey among 238 resident doctors in four selected teaching hospitals in southern Nigeria. Survey questionnaire contained items assessing the KAP of EBM, familiarity with and understanding of key EBM terms, the use of EBM in decision making, barriers militating against EBM and ways to improve EBM adoption. Proportions and summary statistics were reported for the distribution of survey items. RESULTS: Mean number of years in clinical practice was 9.3 ± 4.5 years. Respondents were uniformly distributed in major clinical specialties. The majority (70.5%) were senior registrars. Respondents' understanding of EBM components included; current best clinical evidence (98.3%), clinical expertise (65.5%), and patients' choices (36.6%). Self-rated familiarity with EBM terms was high while perceived understanding of the terms was lower. The least understood concept was heterogeneity (20.6%). The attitude toward EBM was generally positive. Only about half (53.6%) had used medical bibliographic databases within the last 6 months prior to the survey. Barriers against EBM included lack of time (47.1%) and lack of requisite skills (32.4%). Suggestions to improve EBM adoption included training (58.1%), provision of free Wi-Fi, and free access to bibliographic databases (25.2%) and increased political will (23.1%). CONCLUSION: A further understanding of the EBM concept, provision of enabling infrastructure, regular clinical audit and advocacy to hospital management and clinical consultants, may improve the level of adoption of EBM.