ABSTRACT
Background: Domiciliary spirometry (DS) is a novel tool that is widely employed in the assessment of respiratory disease. We assessed real-world feasibility, effectiveness and value of a physiologist-led home spirometry programme in patients with treatment-refractory severe asthma. Methods: Patients were referred and provided with a hand-held DS device. Patients completed baseline measurements in a physiologist-led virtual clinic and were instructed to provide further values during any periods of respiratory symptoms. Outcome measures included prevalence of new obstructed events, DS adherence and uptake of this approach. Results: 112 patients were enrolled from November 2020 to January 2023. 102 individuals, mean±sd age 44±13 years (86% female) with median (IQR) forced expiratory volume in 1â s % predicted 88% (77-97%), successfully recorded baseline spirometry values. During follow-up (24â months), 11 (11%) were identified with new obstructive spirometry and were subsequently able to be commenced on biologic therapy. Patient engagement was poor with median (IQR) of 4 (2-6) attempts of contact made before baseline values were recorded, and 2 (1-3) attempts required to record technically acceptable values. Continued DS use was suboptimal; 34% failed to use their device after baseline and only 10% continued at the end of the study period. The cost of DS measurements was greater than a single hospital-based visit but enables multiple event capture. Conclusion: Overall, DS measurement uptake was poor, with a minority of patients continuing to use the device at the end of the study period. However, for those that engage, DS provides an alternative approach to traditional hospital-based spirometry measurements that can alter clinical management.
ABSTRACT
BACKGROUND: Despite growing concerns about transmissibility and clinical impact, occult hepatitis B virus (HBV) infection has received little attention in the hepatitis elimination agenda. We aimed to estimate the prevalence of occult HBV infection at a global and regional scale and in specific populations. METHODS: For this systematic review and meta-analysis, we searched the MEDLINE, Embase, Global Health, and Web of Science databases for articles published in any language between Jan 1, 2010, and Aug 14, 2019. We included original articles and conference abstracts of any study design that reported the proportion of HBsAg-negative adults (aged ≥18 years) who are positive for HBV DNA (ie, people with occult HBV infection). The prevalence of occult HBV infection was pooled, using the DerSimonian-Laird random-effects model, in the general population and specific groups defined by the type of study participants (blood donors; other low-risk populations; high-risk populations; and people with advanced chronic liver disease), and stratified by HBV endemicity in each country. We also assessed the performance of anti-HBc as an alternative biomarker to detect occult HBV infection. The study was registered with PROSPERO, CRD42019115490. FINDINGS: 305 of 3962 articles were eligible, allowing a meta-analysis of 140 521 993 individuals tested for HBV DNA. Overall, only two studies evaluated occult HBV infection in the general population, precluding unbiased global and regional estimates of occult HBV infection prevalence. In blood donors, occult HBV infection prevalence mirrored HBV endemicity: 0·06% (95% CI 0·00-0·26) in low-endemicity countries, 0·12% (0·04-0·23) in intermediate-endemicity countries, and 0·98% (0·44-1·72), in high-endemicity countries (p=0·0012). In high-risk groups, occult HBV infection prevalence was substantial, irrespective of endemicity: 5·5% (95% CI 2·9-8·7) in low-endemicity countries, 5·2% (2·5-8·6) in intermediate-endemicity countries, and 12·0% (3·4-24·7) in high-endemicity countries. The pooled sensitivity of anti-HBc to identify occult HBV infection was 77% (95% CI 62-88) and its specificity was 76% (68-83). INTERPRETATION: A substantial proportion of people carry occult HBV infection, especially among high-risk groups across the globe and people living in highly endemic countries. Occult HBV infection should be part of the global viral hepatitis elimination strategy. FUNDING: None.
