ABSTRACT
Objectives: Lab-based polysomnography (PSG), for diagnosing obstructive sleep apnoea (OSA), is a subsidised inpatient service in Singapore’s public healthcare institutions (PHIs). The alternative, home sleep test (HST), is cheaper and can be prescribed in the outpatient setting. Following health technology assessment performed by Agency for Care Effectiveness, HST was listed as a subsidised service in PHIs in May 2019. This study aims to assess the impact of the subsidy decision on sleep tests utilisation. Methods: We conducted an interrupted time series (ITS) analysis using sleep tests utilisation data submitted by PHIs from January 2018 to June 2021. Segmented regression models were used to assess the degree of level change (LC) and trend change (TC) of HST and PSG. Data points during Singapore’s most stringent COVID-19 restrictions were modelled as “wild” points to account for drastic reduction of elective procedures. Autocorrelation was tested and corrected by including an autoregressive or moving average term in the models. Results: Subsidy implementation increased the use of HST, from 12% of all sleep tests pre-subsidy to 26% post-subsidy. Despite multiple periods of interruptions, associated with COVID-19 restrictions, ITS showed subsidy implementation led to significant level change in HST utilisation [LC 36.1 (95% CI: 15.1 - 57.2);TC -0.5 (95% CI: -2.3 - 1.4)]. There was also a trend towards reduction in PSG, though this did not reach statistical significance [LC -44.3 (95% CI: -126.6 - 38.2);TC -2.0 (95% CI: -11.6 - 7.7)]. As HST is much cheaper than PSG, total charge avoided by the healthcare system in 10 years is projected to be in the range of SGD9 million to SGD14 million. Conclusion: Extension of subsidy to HST appeared to have improved accessibility of sleep tests for OSA diagnosis and resulted in cost saving to Singapore’s healthcare system.
ABSTRACT
BACKGROUND: Little is known about the performance of the Roche novel severe acute respiratory syndrome coronavirus 2 antibody (anti-SARS-CoV-2) assay. We provide an extensive evaluation of this fully automated assay on Cobas e801/e602 immunoassay analyzers. METHODS: We assessed the linearity, precision, and throughput of the Roche anti-SARS-CoV-2 assay. Sensitivity was calculated from 349 SARS-CoV-2 polymerase chain reaction (PCR) positive samples; specificity was determined from 715 coronavirus disease 2019 (COVID-19)-naive samples. We examined cross-reactivity against other antibody positive samples [syphilis, rheumatoid factor (RF), antinuclear antibody (ANA), double-stranded DNA (ds-DNA), influenza, dengue, hepatitis B (HBV), hepatitis C (HCV)] and the anti-SARS-CoV-2 kinetics. RESULTS: The assay cut-off index (COI) was linear up to 90.8. The interassay precision was 2.9% for a negative control (COI = 0.1) and 5.1% for a positive control (COI = 3.0). Assay time is 18 min and results are available 1 min later; throughput for 300 samples was 76 min. Only 1 case positive for HBsAg tested falsely positive; specificity was 99.9%. The assay has a sensitivity of 97.1% 14 days after PCR positivity (POS) and 100% at ≥21 days POS; 48.2% of cases had anti-SARS-CoV-2 within 6 days POS. In 11 patients in whom serum was available prior to a positive antibody signal (COI ≥1.0) the interval between the last negative and first positive COI (time to "seroconversion") on average is 3 days (range 1-6 days) and 4 more days (range 1-7) for the anti-SARS-CoV-2 to plateau. CONCLUSION: The Roche anti-SARS-CoV-2 assay shows excellent performance with minimal cross-reactivity from other viral and confounding antibodies. Antibody development and seroconversion appears quite early.