A study protocol for the policy intervention design and development of the implementation strategies for direct access to physiotherapists in primary care: a sequential mixed-method study using implementation mapping and a Delphi survey.

Background: In many Asian jurisdictions, patients are required to obtain referrals from registered doctors before consulting physiotherapists. In contrast, countries such as the United States, the United Kingdom, and Australia have a direct access model for physiotherapists designed across different healthcare settings and under prescribed conditions. While research has demonstrated the benefits of direct access, issues remain on the appropriate policy design for direct access in the context of patient safety and organizational challenges in the implementation.

Association of nirmatrelvir-ritonavir with post-acute sequelae and mortality among patients who are immunocompromised with COVID-19 in Hong Kong: a retrospective cohort study.

Background: The effect of nirmatrelvir-ritonavir on post-COVID-19 outcomes for individuals who are immunocompromised is understudied. We aimed to examine the association of nirmatrelvir-ritonavir with post-acute sequelae and mortality among patients who are immunocompromised and admitted to hospital with COVID-19.

Methods: We did a retrospective cohort study using territory-wide electronic health records from the Hong Kong Hospital Authority and Hong Kong Department of Health.

COVID-19 vaccination modified the effect of nirmatrelvir-ritonavir on post-acute mortality and rehospitalization: a retrospective cohort study.

While previous research examined coronavirus disease 2019 (COVID-19) antiviral-vaccine interactions through exploratory subgroup analysis, none specifically designed for examining this interaction or its impact on post-acute outcomes. This study examined the interaction between nirmatrelvir-ritonavir and complete COVID-19 vaccination on reducing the risk of post-acute outcomes among COVID-19 patients. We followed COVID-19 patients hospitalized between 11 March 2022 and 10 October 2023, until 31 October 2023 in Hong Kong.

Association between asthma and COVID-19 severity during Omicron epidemic: a retrospective cohort study using real-world data.

Background: The available evidence presented inconsistencies and inconclusive findings regarding the associations between co-existing asthma and mortality among COVID-19 patients. The objective of the current study is to investigate the relationship between asthma and severe outcomes after SARS-CoV-2 Omicron infection in an infection-naïve population.

Methods: A retrospective cohort study using propensity score matching was conducted.

Association between meteorological variations and the superspreading potential of SARS-CoV-2 infections.

Background: While many investigations examined the association between environmental covariates and COVID-19 incidence, none have examined their relationship with superspreading, a characteristic describing very few individuals disproportionally infecting a large number of people.

Methods: Contact tracing data of all the laboratory-confirmed COVID-19 cases in Hong Kong from February 16, 2020 to April 30, 2021 were used to form the infection clusters for estimating the time-varying dispersion parameter (k), a measure of superspreading potential. Generalized additive models with identity link function were used to examine the association between negative-log k (larger means higher superspreading potential) and the environmental covariates, adjusted with mobility metrics that account for the effect of social distancing measures.

Effectiveness of BNT162b2 and Sinovac vaccines against the transmission of SARS-CoV-2 during Omicron-predominance in Hong Kong: A retrospective cohort study of COVID-19 cases.

Background: In 2022, SARS-CoV-2 Omicron variants circulated globally, generating concerns about increased transmissibility and immune escape. Hong Kong, having an infection-naive population with a moderate 2-dose vaccine coverage (63% by the end of 2021), experienced a COVID-19 epidemic largely seeded by Omicron BA.2 variants that led to the greatest outbreak in the region to date.

Relationship between antidepressants and severity of SARS-CoV-2 Omicron infection: a retrospective cohort study using real-world data.

Background: Few studies have used real-world data to evaluate the impact of antidepressant use on the risk of developing severe outcomes after SARS-CoV-2 Omicron infection.

Methods: This is a retrospective cohort study using propensity-score matching to examine the relationship between antidepressant use and COVID-19 severity. Inpatient and medication records of all adult COVID-19 patients in Hong Kong during the Omicron-predominated period were obtained.

Changes in all-cause and cause-specific excess mortality before and after the Omicron outbreak of COVID-19 in Hong Kong.

Background: While coronavirus 2019 (COVID-19) deaths were generally underestimated in many countries, Hong Kong may show a different trend of excess mortality due to stringent measures, especially for deaths related to respiratory diseases. Nevertheless, the Omicron outbreak in Hong Kong evolved into a territory-wide transmission, similar to other settings such as Singapore, South Korea, and recently, mainland China. We hypothesized that the excess mortality would differ substantially before and after the Omicron outbreak.

Comparing the incubation period, serial interval, and infectiousness profile between SARS-CoV-2 Omicron and Delta variants.

In January 2022, the SARS-CoV-2 Omicron variants initiated major outbreaks and dominated the transmissions in Hong Kong, displacing an earlier outbreak seeded by the Delta variants. To provide insight into the transmission potential of the emerging variants, we aimed to compare the epidemiological characteristics of the Omicron and Delta variants. We analyzed the line-list clinical and contact tracing data of the SARS-CoV-2 confirmed cases in Hong Kong.

Estimating the serial intervals of SARS-CoV-2 Omicron BA.4, BA.5, and BA.2.12.1 variants in Hong Kong.

Empirical evidence on the epidemiological characteristics of the emerged SARS-CoV-2 variants could shed light on the transmission potential of the virus and strategic outbreak control planning. In this study, by using contact tracing data collected during an Omicron-predominant epidemic phase in Hong Kong, we estimated the mean serial interval of SARS-CoV-2 Omicron BA.4, BA.

Dining-Out Behavior as a Proxy for the Superspreading Potential of SARS-CoV-2 Infections: Modeling Analysis.

Background: While many studies evaluated the reliability of digital mobility metrics as a proxy of SARS-CoV-2 transmission potential, none examined the relationship between dining-out behavior and the superspreading potential of COVID-19.

Objective: We employed the mobility proxy of dining out in eateries to examine this association in Hong Kong with COVID-19 outbreaks highly characterized by superspreading events.

Methods: We retrieved the illness onset date and contact-tracing history of all laboratory-confirmed cases of COVID-19 from February 16, 2020, to April 30, 2021.

Estimation of Vaccine Effectiveness of CoronaVac and BNT162b2 Against Severe Outcomes Over Time Among Patients With SARS-CoV-2 Omicron.

Importance: Few studies have evaluated the waning of vaccine effectiveness against severe outcomes caused by SARS-CoV-2 Omicron infection. Hong Kong is providing inactivated and mRNA vaccines, but the population had limited protection from natural infections before the Omicron variant emerged.

Objective: To examine the change in vaccine effectiveness against hospitalization and mortality due to the Omicron variant over time.

A statistical framework for tracking the time-varying superspreading potential of COVID-19 epidemic.

Timely detection of an evolving event of an infectious disease with superspreading potential is imperative for territory-wide disease control as well as preventing future outbreaks. While the reproduction number (R) is a commonly-adopted metric for disease transmissibility, the transmission heterogeneity quantified by dispersion parameter k, a metric for superspreading potential is seldom tracked. In this study, we developed an estimation framework to track the time-varying risk of superspreading events (SSEs) and demonstrated the method using the three epidemic waves of COVID-19 in Hong Kong.

Experience of a demand-side subsidy scheme for residential long-term care: perspectives of elderly and their carers.

Background: Vouchers, which are demand-side subsidies to targeted groups, are a type of consumer-led near-cash social transfer for specified benefits that have been used in education, health and other sectors. To provide better access to residential care services and an additional choice for elderly people in need, a novel means-tested residential care service voucher has been introduced in Hong Kong for elderly people to purchase places in the private sector to enable consumer-directed care. The objectives of this paper are to analyze the perspectives of voucher users and their carers toward the voucher scheme and to identify key elements in the design that will contribute to meeting the scheme's objectives.

Characterization of Unlinked Cases of COVID-19 and Implications for Contact Tracing Measures: Retrospective Analysis of Surveillance Data.

Background: Contact tracing and intensive testing programs are essential for controlling the spread of COVID-19. However, conventional contact tracing is resource intensive and may not result in the tracing of all cases due to recall bias and cases not knowing the identity of some close contacts. Few studies have reported the epidemiological features of cases not identified by contact tracing ("unlinked cases") or described their potential roles in seeding community outbreaks.

Long-term effectiveness of elderly health care voucher scheme strategies: a system dynamics simulation analysis.

Background: The elderly healthcare voucher (EHCV) scheme is expected to lead to an increase in the number of elderly people selecting private primary healthcare services and reduce reliance on the public sector in Hong Kong. However, studies thus far have reported that this scheme has not received satisfactory responses. In this study, we examined changes in the ratio of visits between public and private doctors in primary care (to measure reliance on the public sector) for different strategic scenarios in the EHCV scheme.

Assessing the impact of non-pharmaceutical interventions on the transmissibility and severity of COVID-19 during the first five months in the Western Pacific Region.

While most countries in the Western Pacific Region (WPR) had similar trajectories of COVID-19 from January to May, their implementations of non-pharmaceutical interventions (NPIs) differed by transmission stages. To offer a better understanding for an implementation of multidisciplinary policies in COVID-19 control, we compared the impact of NPIs by assessing the transmissibility and severity of COVID-19 in different phases of the epidemic during the first five months in WPR. In this study, we estimated the piecewise instantaneous reproduction number ( ) and the reporting delay-adjusted case-fatality ratio (dCFR) of COVID-19 in seven WPR jurisdictions: Hong Kong Special Administrative Region, Japan, Malaysia, Shanghai, Singapore, South Korea, and Taiwan.

An evaluation of universal vouchers as a demand-side subsidy to change primary care utilization: A retrospective analysis of longitudinal services utilisation and voucher claims data from a survey cohort in Hong Kong.

To incentivize private primary care utilization and reduce reliance on public healthcare services, Elderly Healthcare Voucher Scheme has been implemented to provide a voucher entitlement to entire older resident population for subsidising their purchase of unspecified primary healthcare services in the private sector. Our study assessed whether voucher usage is associated with reduced utilization of public healthcare services. We retrieved the public healthcare services utilization and voucher transaction data of a survey cohort of 551 participants, who were age eligible for the scheme since 2009, over the period 2009-2015.