Gaming disorder has become a global concern and it could have a variety of health and social consequences. The trauma model has been applied to the understanding of different types of addictions as behavioral addictions can sometimes be conceptualized as self-soothing strategies to avoid trauma-related stressors or triggers. However, much less is known about the relationship between trauma exposure and gaming disorder.

To inform prevention and intervention strategies and to facilitate further research, we conducted the first scoping review to explore and summarize the literature on the relationship between trauma and gaming disorder.

A systematic search was conducted on the Web of Science, Scopus and ProQuest. We looked for original studies published in English that included a measure of trauma exposure and a measure of gaming disorder symptoms, as well as quantitative data regarding the relationship between trauma exposure and gaming disorder.

The initial search generated 412 articles, of which 15 met the inclusion criteria. All of them were cross-sectional studies, recruiting participants from both clinical and non-clinical populations. Twelve of them (80%) reported significant correlations between trauma exposure and the severity of gaming disorder symptoms (r = 0.18 to 0.46, p < 0.010). Several potential mediators, including depressive symptoms and dissociative experiences, have been identified. One study found that parental monitoring moderated the relationship between trauma and gaming disorder symptoms. No studies reported the prevalence of trauma or trauma-related symptoms among people with gaming disorder.

There is some evidence supporting the association between trauma and gaming disorder, at small to medium effect sizes. Future studies should investigate the mediators and moderators underlying the relationship between trauma and gaming disorder. The longitudinal relationship between trauma exposure and the development of gaming disorder should be clarified. A trauma-informed approach may be a helpful strategy to alleviate gaming disorder symptoms.

None Declared

Although there is an increasing interest in making mental health services (MHS) accessible to youths, there is limited ground-up involvement of youths while designing MHS in Asian settings.

This qualitative study sought to understand what youths considered as important elements of youth centric MHS and how these could be designed to improve access by youths in Singapore.

We conducted seven focus group discussions, and four semi-structured interviews with 50 multiracial youths aged 15-35 years in Singapore - a high-income Southeast Asian country. Purposive sampling allowed adequate representation of age, gender, and race (mainly Chinese, Malay, and Indian) groups. Participants reflected on the features of an ideal MHS for youths and how these could improve youths’ attitude and access to services. Participants also shared their preferences and additional opinions for culturally tailored and age appropriate MHS. Framework analysis using the ‘Conceptual Framework of Access to Healthcare’ (Levesque et al. Int J Equity Health 2013, 12:18) was used to code transcripts and identify the key themes (Ritchie & Spencer. In Analyzing qualitative data, 1994).

The average age of the participants was 24 years. About one third of the participants had accessed MHS in the past. Three key themes were identified – making facilities ‘approachable’, ‘available and appropriate’ and ‘affordable’. (i) Making facilities approachable related to having non-stigmatizing, non-threatening and welcoming aesthetics, organizational culture, and personnel. The participants also recommended a range of professional services, digital tools, and online features to enhance the approachability of MHS designed for youths. (ii) Flexible operating hours, easy appointment management, accessible location, and easy availability to youths with unique needs (e.g., employed youths) or socio-cultural backgrounds were necessary for making facilities available and accessible to youths. (iii) While sharing challenges of family involvement in the help-seeking process, most of the participants, particularly those in the lower ages, talked about tailoring MHS to the ability of youths to pay for the services. Preferences such as having cheaper services for teenagers and initial contacts, offering more non-medical but trained professionals, and considering shorter in-person counselling sessions, followed by free online options were brought up by the participants.

The study provided insights into multiple aspects of MHS and how these could be designed to cater to the needs of youths in Singapore from their perspective. MHS that incorporate non-stigmatizing, flexible, non-threatening and affordable design approaches could improve help-seeking and early interventions in youths.

None Declared

In the United States, lesbian, gay, bisexual, transgender, queer, intersex, asexual and other sexually minoritized and gender expansive (LGBTQ+) young adults are at increased risk for experiencing mental health inequities, including anxiety, depression and psychological distress-related challenges associated with their sexual and gender identities. LGBTQ+ young adults may have unique experiences of sexual and gender minority-related vulnerability because of LGBTQ+-related minority stress and stressors, such as heterosexism, family rejection, identity concealment and internalized homophobia. Identifying and understanding specific LGBTQ+-related minority stress experiences and their complex roles in contributing to mental health burden among LGBTQ+ young adults could inform public health efforts to eliminate mental health inequities experienced by LGBTQ+ young adults. Therefore, this study sought to form empirically based risk profiles (i.e., latent classes) of LGBTQ+ young adults based on their experiences with familial heterosexist experiences, LGBTQ+-related family rejection, internalized LGBTQ+-phobia and LGBTQ+ identity concealment, and then identify associations of derived classes with psychological distress.

We recruited and enrolled participants using nonprobability, cross-sectional online survey data collected between May and August 2020 (N = 482). We used a three-step latent class analysis (LCA) approach to identify unique classes of response patterns to LGBTQ+-related minority stressor subscale items (i.e., familial heterosexist experiences, LGBTQ+-related family rejection, internalized LGBTQ+-phobia and LGBTQ+ identity concealment), and multinomial logistic regression to characterize the associations between the derived classes and psychological distress.

Five distinct latent classes emerged from the LCA: (1) low minority stress, (2) LGBTQ+ identity concealment, (3) family rejection, (4) moderate minority stress and (5) high minority stress. Participants who were classified in the high and moderate minority stress classes were more likely to suffer from moderate and severe psychological distress compared to those classified in the low minority stress class. Additionally, relative to those in the low minority stress class, participants who were classified in the LGBTQ+ identity concealment group were more likely to suffer from severe psychological distress.

Familial heterosexist experiences, LGBTQ+-related family rejection, internalized LGBTQ+-phobia and LGBTQ+ identity concealment are four constructs that have been extensively examined as predictors for mental health outcomes among LGBTQ+ persons, and our study is among the first to reveal nuanced gradients of these stressors. Additionally, we found that more severe endorsement of minority stress was associated with greater psychological distress. Given our study results and the previously established negative mental health impacts of minority stressors among LGBTQ+ young adults, findings from our study can inform research, practice, and policy reform and development that could prevent and reduce mental health inequities among LGBTQ+ young adults.

Population-wide restrictions during the COVID-19 pandemic may create barriers to mental health diagnosis. This study aims to examine changes in the number of incident cases and the incidence rates of mental health diagnoses during the COVID-19 pandemic.

By using electronic health records from France, Germany, Italy, South Korea and the UK and claims data from the US, this study conducted interrupted time-series analyses to compare the monthly incident cases and the incidence of depressive disorders, anxiety disorders, alcohol misuse or dependence, substance misuse or dependence, bipolar disorders, personality disorders and psychoses diagnoses before (January 2017 to February 2020) and after (April 2020 to the latest available date of each database [up to November 2021]) the introduction of COVID-related restrictions.

A total of 629,712,954 individuals were enrolled across nine databases. Following the introduction of restrictions, an immediate decline was observed in the number of incident cases of all mental health diagnoses in the US (rate ratios (RRs) ranged from 0.005 to 0.677) and in the incidence of all conditions in France, Germany, Italy and the US (RRs ranged from 0.002 to 0.422). In the UK, significant reductions were only observed in common mental illnesses. The number of incident cases and the incidence began to return to or exceed pre-pandemic levels in most countries from mid-2020 through 2021.

Healthcare providers should be prepared to deliver service adaptations to mitigate burdens directly or indirectly caused by delays in the diagnosis and treatment of mental health conditions.

Self-compassion (SC) describes an emotionally positive attitude extended toward ourselves when we suffer, consisting of three main components; self-kindness, common humanity, and mindfulness (Germer & Neff, 2013). SC entails being warm and understanding towards ourselves when encountering pain or personal shortcomings, rather than ignoring them or flagellating ourselves with self-criticism. SC also involves recognizing that suffering and failure are part of the shared human experience rather than isolating. In addition, SC requires taking a mindful approach to one’s feelings and thoughts, without judgment of them.

Self-compassion (SC) involves taking an emotionally positive attitude towards oneself when suffering. Although SC has positive effects on mental well-being as well as a protective role in preventing depression and anxiety in healthy individuals, few studies on white matter (WM) microstructures in neuroimaging studies of SC has been studied.

Magnetic resonance imaging data were acquired from 71 healthy participants with measured levels of SC and its six subscales. Mirroring network as WM regions of interest were analyzed using tract-based spatial statistics (TBSS). After the WM regions associated with SC were extracted, exploratory correlation analysis with the self-forgiveness scale, the coping scale, and the world health organization quality of life scale abbreviated version was performed.

We found that self-compassion scale (SCS) total scores were negatively correlated with the fractional anisotropy (FA) values of the superior longitudinal fasciculus (SLF) in healthy individuals. The self-kindness and mindfulness subscale scores of SCS were also negatively correlated with FA values of the same regions. The FA values of SLF related to SC were found to be negatively correlated with the total scores of self-forgiveness scale, and self-control coping strategy and confrontation coping strategy.

Our findings suggest that levels of SC and its self-kindness and mindfulness components may be negatively associated with DMN-related WM microstructures in healthy individuals. These less WM microstructures may be associated with positive personal attitudes, such as self-forgiveness, self-control and active confrontational strategies.

None Declared

Preventing the occurrence of depression/anxiety and suicide during adolescence can lead to substantive health gains over the course of an individual person’s life. This study set out to identify the expected population-level costs and health impacts of implementing universal and indicated school-based socio-emotional learning (SEL) programs in different country contexts.

A Markov model was developed to examine the effectiveness of delivering universal and indicated school-based SEL programs to prevent the onset of depression/anxiety and suicide deaths among adolescents. Intervention health impacts were measured in healthy life years gained (HLYGs) over a 100-year time horizon. Country-specific intervention costs were calculated and denominated in 2017 international dollars (2017 I$) under a health systems perspective. Cost-effectiveness findings were subsequently expressed in terms of I$ per HLYG. Analyses were conducted on a group of 20 countries from different regions and income levels, with final results aggregated and presented by country income group – that is, low and lower middle income countries (LLMICs) and upper middle and high-income countries (UMHICs). Uncertainty and sensitivity analyses were conducted to test model assumptions.

Implementation costs ranged from an annual per capita investment of I$0.10 in LLMICs to I$0.16 in UMHICs for the universal SEL program and I$0.06 in LLMICs to I$0.09 in UMHICs for the indicated SEL program. The universal SEL program generated 100 HLYGs per 1 million population compared to 5 for the indicated SEL program in LLMICs. The cost per HLYG was I$958 in LLMICS and I$2,006 in UMHICs for the universal SEL program and I$11,123 in LLMICs and I$18,473 in UMHICs for the indicated SEL program. Cost-effectiveness findings were highly sensitive to variations around input parameter values involving the intervention effect sizes and the disability weight used to estimate HLYGs.

The results of this analysis suggest that universal and indicated SEL programs require a low level of investment (in the range of I$0.05 to I$0.20 per head of population) but that universal SEL programs produce significantly greater health benefits at a population level and therefore better value for money (e.g., less than I$1,000 per HLYG in LLMICs). Despite producing fewer population-level health benefits, the implementation of indicated SEL programs may be justified as a means of reducing population inequalities that affect high-risk populations who would benefit from a more tailored intervention approach.

Visual perceptual deficit commonly occurs in people with schizophrenia. The Test of Visual Perceptual Skills-4th Edition (TVPS-4) is a motor-free visual perceptual measure, which includes seven subtests: visual discrimination, visual memory, spatial relationships, form constancy, sequential memory, visual figure-ground, and visual closure. However, convergent validity and ecological validity of the TVPS-4 is largely unknown, which limits its use in clinical and research settings.

The purpose of this study was to examine convergent validity and ecological validity in people with schizophrenia.

Ninety-nine people with schizophrenia were assessed the TVPS-4, the Mini Mental State Examination (MMSE), the Behavioral Assessment of the Dysexecutive Syndrome (BADS), and the Activities of Daily Living Rating Scale III (ADLRS-III). To evaluate convergent validity, Pearson’s r were calculated among the TVPS-4 and two cognitive measures (the MMSE and the BADS). To evaluate ecological validity, we computed correlation (r) between the TVPS-4 and the ADLRS-III.

The TVPS-4 total score showed moderate correlations with two cognitive measures (r=0.65-0.70). The seven TVSP-4 domains revealed moderate correlations with two cognitive measures (r=0.42-0.69). Moderate correlation (r=0.56) was found between the TVPS-4 total score and the ADLRS-III. Moderate to high correlations (r=0.33-0.61) were noticed among the seven TVPS-4 domains and the ADLRS-III.

The TVPS-4 has good convergent validity and ecological validity in people with schizophrenia. The multiple domains of the TVPS-4 are useful to comprehensively identify visual perception deficits in people with schizophrenia. The TVPS-4 can adequately exhibit the degree of living independently in people with schizophrenia.

No significant relationships.

The impact of the coronavirus disease 2019 (COVID-19) pandemic on mental health is still being unravelled. It is important to identify which individuals are at greatest risk of worsening symptoms. This study aimed to examine changes in depression, anxiety and post-traumatic stress disorder (PTSD) symptoms using prospective and retrospective symptom change assessments, and to find and examine the effect of key risk factors.

Online questionnaires were administered to 34 465 individuals (aged 16 years or above) in April/May 2020 in the UK, recruited from existing cohorts or via social media. Around one-third (n = 12 718) of included participants had prior diagnoses of depression or anxiety and had completed pre-pandemic mental health assessments (between September 2018 and February 2020), allowing prospective investigation of symptom change.

Prospective symptom analyses showed small decreases in depression (PHQ-9: −0.43 points) and anxiety [generalised anxiety disorder scale – 7 items (GAD)-7: −0.33 points] and increases in PTSD (PCL-6: 0.22 points). Conversely, retrospective symptom analyses demonstrated significant large increases (PHQ-9: 2.40; GAD-7 = 1.97), with 55% reported worsening mental health since the beginning of the pandemic on a global change rating. Across both prospective and retrospective measures of symptom change, worsening depression, anxiety and PTSD symptoms were associated with prior mental health diagnoses, female gender, young age and unemployed/student status.

We highlight the effect of prior mental health diagnoses on worsening mental health during the pandemic and confirm previously reported sociodemographic risk factors. Discrepancies between prospective and retrospective measures of changes in mental health may be related to recall bias-related underestimation of prior symptom severity.

For infants born in the contemporary era of neonatal care, little is known about adult mental health outcomes of extremely preterm birth (EP; <28 weeks' gestation) or extremely low birthweight (ELBW; <1000 g). This study aimed to compare attention deficit hyperactivity disorder (ADHD), anxiety, mood, and substance use disorder prevalence in young adults born EP/ELBW and normal birthweight (NBW; >2499 g) controls, and to compare change in prevalence of mental health symptoms and disorders from 18 to 25 years.

Participants were a prospective geographical cohort of 297 consecutive survivors born EP/ELBW during 1991–1992 and 260 NBW controls. At age 25 years, 174 EP/ELBW and 139 NBW participants completed the Adult ADHD Rating Scale, Structured Clinical Interview for DSM-IV Disorders, Beck Anxiety Inventory, and Center for Epidemiologic Studies Depression Scale-Revised. Data from follow-up at 18 years were also utilized. Multiple imputation was used to account for attrition.

Mental health outcomes at 25 years were similar between groups: prevalence rates were ADHD 7% v. 5%; anxiety 32% v. 27%; mood 38% v. 35%; substance use 12% v. 14% in the EP/ELBW and NBW groups, respectively. In both groups, ADHD declined between 18 and 25 years [odds ratio (OR) per year = 0.87, 95% confidence interval (CI) 0.79–0.95], and generalized anxiety disorder and major depressive episode became more common (OR 1.22, 95% CI 1.10–1.35 per year; OR 1.20, 95% CI 1.10–1.30 respectively).

This contemporary EP/ELBW cohort has comparable young adult mental health outcomes to controls, and similar patterns of change in mental health from late adolescence.

Young people are most vulnerable to suicidal behaviours but least likely to seek help. A more elaborate study of the intrinsic and extrinsic correlates of suicidal ideation and behaviours particularly amid ongoing population-level stressors and the identification of less stigmatising markers in representative youth populations is essential.

Participants (n = 2540, aged 15–25) were consecutively recruited from an ongoing large-scale household-based epidemiological youth mental health study in Hong Kong between September 2019 and 2021. Lifetime and 12-month prevalence of suicidal ideation, plan, and attempt were assessed, alongside suicide-related rumination, hopelessness and neuroticism, personal and population-level stressors, family functioning, cognitive ability, lifetime non-suicidal self-harm, 12-month major depressive disorder (MDD), and alcohol use.

The 12-month prevalence of suicidal ideation, ideation-only (no plan or attempt), plan, and attempt was 20.0, 15.4, 4.6, and 1.3%, respectively. Importantly, multivariable logistic regression findings revealed that suicide-related rumination was the only factor associated with all four suicidal outcomes (all p < 0.01). Among those with suicidal ideation (two-stage approach), intrinsic factors, including suicide-related rumination, poorer cognitive ability, and 12-month MDE, were specifically associated with suicide plan, while extrinsic factors, including coronavirus disease 2019 (COVID-19) stressors, poorer family functioning, and personal life stressors, as well as non-suicidal self-harm, were specifically associated with suicide attempt.

Suicide-related rumination, population-level COVID-19 stressors, and poorer family functioning may be important less-stigmatising markers for youth suicidal risks. The respective roles played by not only intrinsic but also extrinsic factors in suicide plan and attempt using a two-stage approach should be considered in future preventative intervention work.

Brief measurements of the subjective experience of stress with good predictive capability are important in a range of community mental health and research settings. The potential for large-scale implementation of such a measure for screening may facilitate early risk detection and intervention opportunities. Few such measures however have been developed and validated in epidemiological and longitudinal community samples. We designed a new single-item measure of the subjective level of stress (SLS-1) and tested its validity and ability to predict long-term mental health outcomes of up to 12 months through two separate studies.

We first examined the content and face validity of the SLS-1 with a panel consisting of mental health experts and laypersons. Two studies were conducted to examine its validity and predictive utility. In study 1, we tested the convergent and divergent validity as well as incremental validity of the SLS-1 in a large epidemiological sample of young people in Hong Kong (n = 1445). In study 2, in a consecutively recruited longitudinal community sample of young people (n = 258), we first performed the same procedures as in study 1 to ensure replicability of the findings. We then examined in this longitudinal sample the utility of the SLS-1 in predicting long-term depressive, anxiety and stress outcomes assessed at 3 months and 6 months (n = 182) and at 12 months (n = 84).

The SLS-1 demonstrated good content and face validity. Findings from the two studies showed that SLS-1 was moderately to strongly correlated with a range of mental health outcomes, including depressive, anxiety, stress and distress symptoms. We also demonstrated its ability to explain the variance explained in symptoms beyond other known personal and psychological factors. Using the longitudinal sample in study 2, we further showed the significant predictive capability of the SLS-1 for long-term symptom outcomes for up to 12 months even when accounting for demographic characteristics.

The findings altogether support the validity and predictive utility of the SLS-1 as a brief measure of stress with strong indications of both concurrent and long-term mental health outcomes. Given the value of brief measures of mental health risks at a population level, the SLS-1 may have potential for use as an early screening tool to inform early preventative intervention work.

Depression and anxiety are among the most common mental health conditions treated in primary care. They frequently co-occur and involve recommended treatments that overlap. Evidence from randomised controlled trials (RCTs) shows specific stepped care interventions to be cost-effective in improving symptom remission. However, most RCTs have focused on either depression or anxiety, which limits their generalisability to routine primary care settings. This study aimed to evaluate the cost-effectiveness of a collaborative stepped care (CSC) intervention to treat depression and/or anxiety among adults in Australian primary care settings.

A quasi-decision tree model was developed to evaluate the cost-effectiveness of a CSC intervention relative to care-as-usual (CAU). The model adapted a CSC intervention described in a previous Dutch RCT to the Australian context. This 8-month, cluster RCT recruited patients with depression and/or anxiety (n = 158) from 30 primary care clinics in the Netherlands. The CSC intervention involved two steps: (1) guided self-help with a nurse at a primary care clinic; and (2) referral to specialised mental healthcare. The cost-effectiveness model adopted a health sector perspective and synthesised data from two main sources: RCT data on intervention pathways, remission probabilities and healthcare service utilisation; and Australia-specific data on demography, epidemiology and unit costs from external sources. Incremental costs and incremental health outcomes were estimated across a 1-year time horizon. Health outcomes were measured as disability-adjusted life years (DALYs) due to remitted cases of depression and/or anxiety. Incremental cost-effectiveness ratios (ICERs) were measured in 2019 Australian dollars (A$) per DALY averted. Uncertainty and sensitivity analyses were performed to test the robustness of cost-effectiveness findings.

The CSC intervention had a high probability (99.6%) of being cost-effective relative to CAU. The resulting ICER (A$5207/DALY; 95% uncertainty interval: dominant to 25 345) fell below the willingness-to-pay threshold of A$50 000/DALY. ICERs were robust to changes in model parameters and assumptions.

This study found that a Dutch CSC intervention, with nurse-delivered guided self-help treatment as a first step, could potentially be cost-effective in treating depression and/or anxiety if transferred to the Australian primary care context. However, adaptations may be required to ensure feasibility and acceptability in the Australian healthcare context. In addition, further evidence is needed to verify the real-world cost-effectiveness of the CSC intervention when implemented in routine practice and to evaluate its effectiveness/cost-effectiveness when compared to other viable stepped care interventions for the treatment of depression and/or anxiety.

The coronavirus disease 2019 (COVID-19) pandemic represents an unprecedented threat to mental health. Herein, we assessed the impact of COVID-19 on subthreshold depressive symptoms and identified potential mitigating factors.

Participants were from Depression Cohort in China (ChiCTR registry number 1900022145). Adults (n = 1722) with subthreshold depressive symptoms were enrolled between March and October 2019 in a 6-month, community-based interventional study that aimed to prevent clinical depression using psychoeducation. A total of 1506 participants completed the study in Shenzhen, China: 726 participants, who completed the study between March 2019 and January 2020 (i.e. before COVID-19), comprised the ‘wave 1’ group; 780 participants, who were enrolled before COVID-19 and completed the 6-month endpoint assessment during COVID-19, comprised ‘wave 2’. Symptoms of depression, anxiety and insomnia were assessed at baseline and endpoint (i.e. 6-month follow-up) using the Patient Health Questionnaire-9 (PHQ-9), Generalised Anxiety Disorder-7 (GAD-7) and Insomnia Severity Index (ISI), respectively. Measures of resilience and regular exercise were assessed at baseline. We compared the mental health outcomes between wave 1 and wave 2 groups. We additionally investigated how mental health outcomes changed across disparate stages of the COVID-19 pandemic in China, i.e. peak (7–13 February), post-peak (14–27 February), remission plateau (28 February−present).

COVID-19 increased the risk for three mental outcomes: (1) depression (odds ratio [OR] = 1.30, 95% confidence interval [CI]: 1.04–1.62); (2) anxiety (OR = 1.47, 95% CI: 1.16–1.88) and (3) insomnia (OR = 1.37, 95% CI: 1.07–1.77). The highest proportion of probable depression and anxiety was observed post-peak, with 52.9% and 41.4%, respectively. Greater baseline resilience scores had a protective effect on the three main outcomes (depression: OR = 0.26, 95% CI: 0.19–0.37; anxiety: OR = 1.22, 95% CI: 0.14–0.33 and insomnia: OR = 0.18, 95% CI: 0.11–0.28). Furthermore, regular physical activity mitigated the risk for depression (OR = 0.79, 95% CI: 0.79–0.99).

The COVID-19 pandemic exerted a highly significant and negative impact on symptoms of depression, anxiety and insomnia. Mental health outcomes fluctuated as a function of the duration of the pandemic and were alleviated to some extent with the observed decline in community-based transmission. Augmenting resiliency and regular exercise provide an opportunity to mitigate the risk for mental health symptoms during this severe public health crisis.

Due to shortages of N95 respirators during the coronavirus disease 2019 (COVID-19) pandemic, it is necessary to estimate the number of N95s required for healthcare workers (HCWs) to inform manufacturing targets and resource allocation.

We developed a model to determine the number of N95 respirators needed for HCWs both in a single acute-care hospital and the United States.

For an acute-care hospital with 400 all-cause monthly admissions, the number of N95 respirators needed to manage COVID-19 patients admitted during a month ranges from 113 (95% interpercentile range [IPR], 50–229) if 0.5% of admissions are COVID-19 patients to 22,101 (95% IPR, 5,904–25,881) if 100% of admissions are COVID-19 patients (assuming single use per respirator, and 10 encounters between HCWs and each COVID-19 patient per day). The number of N95s needed decreases to a range of 22 (95% IPR, 10–43) to 4,445 (95% IPR, 1,975–8,684) if each N95 is used for 5 patient encounters. Varying monthly all-cause admissions to 2,000 requires 6,645–13,404 respirators with a 60% COVID-19 admission prevalence, 10 HCW–patient encounters, and reusing N95s 5–10 times. Nationally, the number of N95 respirators needed over the course of the pandemic ranges from 86 million (95% IPR, 37.1–200.6 million) to 1.6 billion (95% IPR, 0.7–3.6 billion) as 5%–90% of the population is exposed (single-use). This number ranges from 17.4 million (95% IPR, 7.3–41 million) to 312.3 million (95% IPR, 131.5–737.3 million) using each respirator for 5 encounters.

We quantified the number of N95 respirators needed for a given acute-care hospital and nationally during the COVID-19 pandemic under varying conditions.