The COVID-19 pandemic led to increases in anxiety, depression and overall psychological distress. 1 There were adverse psychosocial impacts on various sociocultural groups in Canada. 2 There are reports of lasting anxiety following COVID-19 infection3 and this experience evolved over time as the pandemic progressed. A recent review of longitudinal studies examining changes in mental health and lifestyle among college students during the COVID-19 pandemic revealed increases in anxiety, mood disorders, alcohol use, sedentary behaviour, internet use and a decrease in physical activity. 4 Healthcare workers also experienced significant levels of anxiety, especially those on the frontline and nurses because they were responsible for the care of patients with COVID-19 and more mentally overwhelmed by the lack of specific treatment guidelines or support. 5 A rapid review of the impact of COVID-19 on the mental health of healthcare workers identified underlying organic illness, female gender, concern about family, fear of infection, lack of personal protective equipment (PPE) and close contact with COVID-19 as risk factors associated with adverse mental health outcomes. 6
There was considerable psychological impact of the pandemic on the mental health outcomes of dentists worldwide as well. 7 Prior to the COVID-19 pandemic, literature has reported high rates of suicidality, burnout, stress, anxiety and depression among dentists. 8,9 Dental settings present a potentially high risk of COVID-19 cross-infection as dental care workers work in closed environments and conduct aerosol-generating procedures.5 Many dentists in Canada reported increased work-related stress as their tasks increased significantly during the pandemic. 10 The early months of the pandemic were complicated by personal protective equipment (PPE) shortages and heightened anxieties among patients and dental staff. 11 Despite that COVID-19 vaccines were rapidly administered, starting in December 2020 and public health restrictions were progressively lifted thereafter, authorities continued urging dentists to remain vigilant. 12 Anxiety and depression in US dental healthcare workers during the pandemic were associated with demographic and professional characteristics as well as perceived risk of COVID-19. 13
In China, the frontline dental staff were more likely to suffer from anxiety disorders than the general public. 14 Older age, sufficient personal protective measures and good relationships with colleagues and patients were factors associated with decreased anxiety among them during the pandemic. 14 Furthermore, vaccination against COVID-19 is an effective tool to control the spread of this infectious disease15 and studies have shown that the anxiety levels of vaccinated healthcare providers were lower compared to the non-vaccinated healthcare providers. 15
Elevated levels of stress, anxiety and depression could have long-term psychological implications on all healthcare workers, 16 therefore it is of paramount importance to identify the risk and protective factors associated with COVID-19 related and generalized anxiety in dentists for their long-term psychological well-being.
A number of instruments have been developed and validated for assessing fear, anxiety and stress related to COVID-19 (e.g., the Fear of COVID-19 Scale17, Multidimensional Assessment of COVID-19 related fears18, Coronavirus Anxiety Scale19, COVID-19 Anxiety Scale20, COVID Stress Scales21, Perceived Coronavirus Threat Questionnaire22). A widely used instrument, the COVID-19 Anxiety Syndrome Scale23 was initially developed to reliably assess the presence of COVID-19 anxiety syndrome features in a general US adult population. Later, it was validated in several countries including Iran, 24 Italy, 25 Indonesia, 26 Brazil, 27 Saudi Arabia28, Canada29 and Greece. 30 A previous study in Canada has evaluated the validity and reliability of the C-19ASS in English and French among Canadian dentists and it can be used to evaluate COVID-19 related anxiety in this population. 29
As a follow-up to this, further validation of this anxiety measure in Canadian dentists can be done by assessment of a longitudinal measurement aspect, responsiveness (sensitivity to change) which is an important psychometric property of a measure. Responsiveness is the ability of a measure to detect a real change in the true value of an underlying construct. 31 Due to heightened interest in the impact of the COVID-19 pandemic on the psychological health of dentists, numerous cross-sectional studies have been conducted during this epidemiological crisis32–36, however, they have not reported how COVID-19 related anxiety changed over time among dentists as the pandemic evolved. There is a pressing need for further longitudinal studies to improve our knowledge on this subject.
Previously, studies have tested whether COVID-19 risk was positively correlated with mental health concerns among dental healthcare workers. 13 For this purpose, COVID-19 case rate per 100,000 people in each US state and territory from the Centers for Disease Control and Prevention (CDC) for the 7 days before each survey were obtained. 13 Data on the count of COVID-19 cases reported in Canada was extracted from https://health-infobase.canada.ca/covid-19/ to estimate the extent to which COVID-19 disease burden is associated with salivary cortisol levels in dentists during 1 year. 11
To our knowledge, the responsiveness (sensitivity to change over time) of the C-19ASS among this population during the COVID-19 pandemic has not been reported by any studies. There is a need to further validate the C-19ASS among Canadian dentists by investigating its responsiveness (sensitivity to change over time) using longitudinal data. Further research regarding risk factors associated with COVID-19 related anxiety in dentists practising in Canada is warranted in order to build a resilient workforce. Adequate evidence is required about particularly vulnerable groups among dentists practising in Canada to provide targeted psychological support to them.
Therefore, the objectives of the present study were 1) to estimate the sensitivity to change over time of the C-19ASS among a sample of Canadian dentists; 2) to identify factors associated with COVID-19 related anxiety in Canadian dentists over time and 3) to estimate the differences in the anxiety levels in dentists in Canada following vaccination against SARS-CoV2. We tested the following hypotheses: 1) With increased time during the COVID-19 pandemic, the anxiety levels of the dentists decreased; 2) With increases and decreases in the COVID-19 disease prevalence in the province in which the dentists were working, their anxiety levels similarly increased and decreased.