A longitudinal study of COVID-19 preventive behavior fatigue in Hong Kong: a city with previous pandemic experience.

BACKGROUND: In addition to high vaccination levels, COVID-19 control requires uptake and continued adherence to personal hygiene and social distancing behaviors. It is unclear whether residents of a city with successive experience in worldwide pandemics such as SARS, would quickly adopt and maintain preventive behaviors. METHODS: A population-based, longitudinal telephone survey was conducted between in first local wave of the COVID-19 pandemic (April 2020) and third local wave (December 2020) (n = 403). The study examined factors associated with personal hygiene and social distancing behavior fatigue, as measured by reduced adherence. RESULTS: Over 9 months, face mask use increased (96.5-100%, p < 0.001). Although habitual hand hygiene remained unchanged (92.0%), blue collar workers and non-working individuals showed higher risk of hand hygiene fatigue. There was a decline (p < 0.05) in avoidance of social gatherings (81.1 to 70.7%), avoidance of public places (52.9-27.5%) and avoidance of international travel (81.9-77.4%) even with rising caseloads. Lowered perception of COVID-19 disease severity was associated with decreased avoidance of social gatherings and public places while lower education was associated with decline in avoidance of social gatherings. CONCLUSION: Even in regions with past pandemic experience, maintaining social distancing behaviors during a protracted pandemic remains a major public health challenge.

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. Design, Setting, and Participants: This case-control study included adults with SARS-CoV-2 Omicron variant infection who died or were hospitalized in Hong Kong from January 1 to June 5, 2022 (ie, case participants), and adults with SARS-CoV-2 Omicron, sampled from the public health registry during the study period (ie, control participants), who were matched to case participants by propensity score. Exposures: Vaccination status of the individuals. Main Outcomes and Measures: Estimated vaccine effectiveness against death, death or hospitalization, and death among hospitalized patients. Vaccine effectiveness was calculated as 1 - adjusted odds ratio obtained by conditional logistic regression adjusted with covariates for each period following vaccination. Results: There were 32 823 case participants (25 546 [77.8%] ≥65 years; 16 930 [47.4%] female) and 131 328 control participants (100 041 [76.2%] ≥65 years; 66 625 [46.6%] female) in the sample analyzed for the death or hospitalization outcome. Vaccine effectiveness against death or hospitalization was maintained for at least 6 months after the second dose of both CoronaVac (74.0%; 95% CI, 71.8%-75.8%) and BNT162b2 (77.4%; 95% CI, 75.5%-79.0%) vaccines. Vaccine effectiveness against death in those aged 18 to 49 years was 86.4% (95% CI, 85.8%-87.0%) and 92.9% (95% CI, 92.6%-93.2%) for those receiving 2 doses of CoronaVac and BNT162b2, respectively, while for patients aged 80 years or older, it dropped to 61.4% (95% CI, 59.8%-63.2%) and 52.7% (95% CI, 50.2%-55.6%) for CoronaVac and BNT162b2, respectively. Nevertheless, overall vaccine effectiveness against death at 4 to 6 months after the third dose was greater than 90% for CoronaVac, BNT162b2, and the mixed vaccine schedule (eg, mixed vaccines: vaccine effectiveness, 92.2%; 95% CI, 89.2%-95.1%). Conclusions and Relevance: While vaccines were generally estimated to be effective against severe outcomes caused by SARS-CoV-2 Omicron infection, this analysis found that protection in older patients was more likely to wane 6 months after the second dose. Hence, a booster dose is recommended for older patients to restore immunity. This is especially critical in a setting like Hong Kong, where third-dose coverage is still insufficient among older residents.

The Effect of Social Isolation on Sarcopenia: A Longitudinal Study among the Middle-Aged and Older Population in China.

INTRODUCTION: Although social isolation is associated with premature death and somatic and mental diseases, evidence of its long-term effect on sarcopenia is scarce. This study aimed to examine the longitudinal association between social isolation and possible sarcopenia. METHODS: We extracted baseline and 4-year follow-up data from the China Health and Retirement Longitudinal Study and included participants aged 45 years or above. Social isolation was measured by factors including living alone, marital status, frequency of contact with adult children and friends, and participation in social activity. The change in social isolation from baseline to follow-up was classified into stable, progressive, and regressive groups. Possible sarcopenia was detected using the handgrip strength and five-time chair-stand test. Using mixed-effects logistic regression, we studied the effect of baseline isolation and the change in isolation status on possible sarcopenia at a 4-year follow-up. RESULTS: A total of 5,289 participants aged 45-90 years and without possible sarcopenia at baseline were included. After 4 years, possible sarcopenia was detected in 21.7% (1,146/5,289) of the participants. Compared with the low social isolation group, the middle (OR = 1.53, 95% confidence interval [CI] = 1.16-2.04, p = 0.003) and high social isolation groups (OR = 1.65, 95% CI = 1.26-2.18, p < 0.001) were associated with a higher risk of possible sarcopenia. Being not married/cohabiting (OR = 1.58, 95% CI = 1.19-2.10, p = 0.002), lack of contact with children (OR = 1.86, 95% CI = 1.21-2.85, p = 0.004), and lack of social activities (OR = 1.26, 95% CI = 1.04-1.53, p = 0.019) were associated with an increased risk of possible sarcopenia. Compared with the stable social isolation group, the progressive group was associated with a greater risk of possible sarcopenia (OR = 1.51, 95% CI = 1.17-1.95, p = 0.001). CONCLUSIONS: Social isolation is associated with an increased risk of possible sarcopenia. Progressive social isolation further elevates the risk. The most vulnerable groups are middle-aged and older people who live alone, are not socially active, and lack contact with their children.

The differential impacts of early detection and accelerated antiretroviral therapy on the epidemiologic trend of sexually acquired HIV infection in Hong Kong.

OBJECTIVES: To assess impacts of early detection and prompt antiretroviral therapy (ART) on the latest epidemiologic situation to inform intervention strategy. METHODS: We analysed data from two clinical cohorts in Hong Kong where sexual transmission accounted for the majority of HIV infections. The two cohorts comprised patients newly diagnosed in 2007-2008 and 2016-2018 respectively. Secular trend and differences between men who have sex with men (MSM) and heterosexual patients were examined. Predictors of late presentation (defined as CD4 ≤350 or AIDS-defining illness within 3 months of diagnosis) and prolonged interval between diagnosis and ART initiation were assessed by multivariable regressions. RESULTS: There were 1,136 newly diagnosed HIV patients with 644 in the first and 492 in the second cohort, a majority (91.7%) presented with sexually acquired infection. There were less MSM in the first than the second cohort (50.3%% vs 87.8%, χ2 = 117.05, p<0.001). The mean (SD) number of days between diagnosis and ART initiation decreased from 514.3 (516.1) to 61.8 (94.2) days across the two cohorts. Younger age, non-Chinese, outpatient-based service and lower CD4 count were predictors of faster ART initiation in the first but not in the second cohort. Interval between diagnosis and ART initiation became highly uniform among groups in the second cohort. Nearly 60% were classified as late presenters in both cohorts. Heterosexuals (aOR 1.58, 95% CI 1.13-2.19) had a higher risk of late presentation. CONCLUSIONS: There was remarkable improvement in acceleration of ART initiation. Clinical implementation of accelerated ART recommendations has been effective for both MSM and heterosexuals. Late presentation was more marked among heterosexuals and remained a problem. The continued phenomenon of late presentation could offset the epidemiologic gains from accelerated ART initiation.

Vaccine Resistance and Hesitancy among Older Adults Who Live Alone or Only with an Older Partner in Community in the Early Stage of the Fifth Wave of COVID-19 in Hong Kong.

Vaccination is an effective way in providing protection against COVID-19 infection and severe outcomes. However, vaccine resistance and hesitancy are a great concern among vulnerable populations including older adults who live alone or only with an older partner. This study examined their vaccination status and reasons and associated factors of vaccine resistance and hesitancy. A cross-sectional study was conducted among older adults living alone or only with an older partner in communities in Hong Kong. Participants were interviewed between October 2021 and February 2022. Logistic regression analyses were employed to examine factors associated with vaccine resistance and hesitancy. Of the 2109 included participants, the mean age was 79.3 years (SD 7.6), 1460 (69.2%) were female, 1334 (63.3%) lived alone, and 1621 (76.9%) were receiving social security support. The vaccine uptake, non-uptake (i.e., resistance), and hesitancy rates were 50.1%, 34.4%, and 15.5%, respectively. The top four reasons for vaccine resistance and hesitancy were "Not feeling in good health" (27%), "Worry about vaccine side effects" (18%), "Feeling no need" (10%), and "Lack of recommendation from doctors" (9%). Vaccine resistance and hesitancy was significantly associated with older age, living alone, more chronic conditions, fewer types of social media use, and lower self-rated health status. Similar associations can be observed in their separate analysis for vaccine resistance and vaccine hesitancy, and ever hospital admission over the past 6 months was additionally related to vaccine hesitancy. Older people who live alone or only with an older partner had a low vaccination rate. Poor health or worry about vaccine side effects were the most common reasons for their vaccine resistance and hesitancy. Actions are greatly needed to improve the uptake rate among this vulnerable population, especially those who were older, have poorer health, and use less social media.

Handgrip strength but not SARC-F score predicts cognitive impairment in older adults with multimorbidity in primary care: a cohort study.

BACKGROUND: Assessing motor function is a simple way to track cognitive impairment. We analysed the associations between cognitive and motor function and assessed the predictive value of two motor function measuring tools for cognitive impairment in older adults with multimorbidity in primary care settings. METHODS: We conducted a prospective cohort study with a 1 year follow-up. Patients aged ≥60 years with ≥2 morbidities were recruited from four primary care clinics. Motor function was assessed using handgrip strength and a sarcopenia screening scale (SARC-F). Cognitive function was measured using the Hong Kong Montreal Cognitive Assessment (HK-MoCA). We defined cognitive impairment as an HK-MoCA score < 22. The associations between cognitive and motor functions were examined from a bidirectional perspective. RESULTS: We included 477 participants (mean age 69.4, 68.6% female) with a mean (SD) HK-MoCA score of 25.5 (3.38), SARC-F score of 1.1 (1.36), and handgrip strength of 21.2 (6.99) kg at baseline. Multivariable linear regression models showed bidirectional cross-sectional associations of the HK-MoCA score and cognitive impairment with SARC-F score and handgrip strength at baseline and 1 year. Cox regression revealed a longitudinal association between baseline handgrip strength and cognitive impairment at 1 year (hazard ratio: 0.48, 95% CI 0.33-0.69) but no longitudinal association between SARC-F and cognitive impairment. Variation in the SARC-F score increased with decreasing HK-MoCA score (Brown-Forsythe test F statistic = 17.9, p < 0.001), while variability in the handgrip strength remained small (modified signed-likelihood ratio test, p < 0.001). CONCLUSIONS: Primary healthcare providers may use handgrip strength to track cognitive function decline in older adults with multimorbidity. However, the SARC-F scale may not have the same predictive value. Further research is needed to evaluate the performance and variability of the SARC-F score in individuals with poor cognitive function.

Recommending COVID-19 Vaccines to Patients: Practice and Concerns of Frontline Family Doctors.

Background: Recommendation from doctors is a well-recognized motivator toward vaccine uptake. Family doctors are in the prime position to advise the public on COVID-19 vaccination. We studied the practice and concerns of frontline family doctors concerning COVID-19 vaccination recommendations to patients. Methods: We conducted a cross-sectional online survey of all family doctors in the Hong Kong College of Family Physicians between June and July 2021. Their practice of making COVID-19 recommendation to patients was assessed. Based on the Health Belief Model, factors associated with doctors' recommendation practices were explored and examined. Multivariate logistic regression models were used to investigate the factors, including COVID-19 vaccine attributes, associated with doctors' practices in making recommendations. Their own vaccination status and psychological antecedents to vaccine hesitancy were measured. Results: A total of 312 family doctors responded (a 17.6% response rate). The proportion of doctors who had received COVID-19 vaccines was 90.1%. The proportion of doctors who would recommend all patients without contraindications for the vaccination was 64.4%. The proportion of doctors who would proactively discuss COVID-19 vaccines with patients was 52.9%. Multivariate logistic regression analysis showed that doctors' own COVID-19 vaccination status was the strongest predictor of family doctors making a recommendation to patients (aOR 12.23 95% CI 3.45-43.33). Longer duration of practice, willingness to initiate the relevant discussion with patients and less worry about vaccine side effects on chronic illness patients were the other factors associated with making a COVID-19 vaccination recommendation. Conclusions: Family doctors should be encouraged to get vaccinated themselves and initiate discussions with patients about COVID-19 vaccines. Vaccine safety data on patients with chronic illness, training and guidelines for junior doctors may facilitate the COVID-19 vaccination recommendation practices of family doctors.