Introduction We investigated the prevalence of new or persistent manifestations experienced by COVID-19 survivors at 3 or more months after their initial infection, collectively known as post-COVID-19 condition (PCC). Methods We searched four electronic databases and major grey literature resources for prospective studies, systematic reviews, authoritative reports and population surveys. A random-effects meta-analysis pooled the prevalence data of 22 symptoms and outcomes. The GRADE approach was used to assess the certainty of evidence. PROSPERO CRD42021231476. Results Of 20 731 identified references, 194 met our inclusion criteria. These studies followed 483 531 individuals with confirmed COVID-19 diagnosis over periods of up to 2 years. Most focused on adults, nearly two-thirds were conducted in Europe and 63% were of high or moderate quality. The supplementary search identified 17 systematic reviews, five authoritative reports and four population surveys that reported on PCC prevalence. Our analysis revealed that more than half of COVID-19 survivors experienced one or more symptoms more than a year after their initial infection. The most common symptoms were fatiguedyspneamemory, sleep or concentration disturbances; depressionand pain. Limitation in returning to work was the most common outcome. Prevalence tended to be higher among females, individuals hospitalized during their initial infection and those who experienced severe COVID-19 illness. Conclusion PCC presents a significant health burden, affecting some groups more than others. This information will help inform health care system policies and services for people living with PCC and those caring for them.

Introduction: Executive functions play a fundamental role in walking by integrating information from cognitive‐motor pathways. Subtle changes in brain and behavior may help identify older adults who are more susceptible to executive function deficits with advancing age due to prefrontal cortex deterioration. This study aims to examine how older adults mitigate executive demands while walking during cognitively demanding tasks.Methods: Twenty healthy older adults (M = 71.8 years, SD = 6.4) performed simple reaction time (SRT), go/no‐go (GNG), n‐back (NBK), and double number sequence (DNS) cognitive tasks of increasing difficulty while walking (i.e., dual task). Functional near infra‐red spectroscopy (fNIRS) was used to measure the hemodynamic response (i.e., oxy‐ [HbO2] and deoxyhemoglobin [HbR]) changes in the prefrontal cortex (PFC) during dual and single tasks (i.e., walking alone). In addition, performance was measured using gait speed (m/s), response time (s), and accuracy (% correct).Results: Using repeated measures ANOVAs, neural findings demonstrated a main effect of task such that ∆HbO2 (p = .047) and ∆HbR (p = .040) decreased between single and dual tasks. An interaction between task and cognitive difficulty (p = .014) revealed that gait speed decreased in the DNS between single and dual tasks. A main effect of task in response time indicated that the SRT response time was faster than all other difficulty levels (p < .001). Accuracy performance declined between single and dual tasks (p = .028) and across difficulty levels (p < .001) but was not significantly different between the NBK and DNS.Conclusion: Findings suggest that a healthy older adult sample might mitigate executive demands using an automatic locomotor control strategy such that shifting conscious attention away from walking during the dual tasks resulted in decreased ∆HbO2 and ∆HbR. However, decreased prefrontal activation was inefficient at maintaining response time and accuracy performance and may be differently affected by increasing cognitive demands.

Executive function and motor control deficits adversely affect gait performance with age, but the neural correlates underlying this interaction during stair climbing remains unclear. Twenty older adults (72.7 ± 6.9 years) completed single tasks: standing and responding to a response time task (SC), ascending or descending stairs (SM_up, SM_down); and a dual-task: responding while ascending or descending stairs (DT_up, DT_down). Prefrontal hemodynamic response changes (∆HbO2, ∆HbR) were examined using functional near-infrared spectroscopy (fNIRS), gait speed was measured using in-shoe smart insoles, and vocal response time and accuracy were recorded. Findings revealed increased ∆HbO2 (p = 0.020) and slower response times (p < 0.001) during dual- versus single tasks. ∆HbR (p = 0.549), accuracy (p = 0.135) and gait speed (p = 0.475) were not significantly different between tasks or stair climbing conditions. ∆HbO2 and response time findings suggest that executive processes are less efficient during dual-tasks. These findings, in addition to gait speed and accuracy maintenance, may provide insights into the neural changes that precede performance declines. To capture the subtle differences between stair ascent and descent and extend our understanding of the neural correlates of stair climbing in older adults, future studies should examine more difficult cognitive tasks.

Subjective cognitive decline (SCD) may represent a preclinical manifestation of objective cognitive impairment. This review consolidated existing findings to determine if dual‐tasks objectively differentiate between individuals with SCD, motoric cognitive risk syndrome (MCR), mild cognitive impairment (MCI), and dementia. MEDLINE, Embase, PsycINFO, CENTRAL, AgeLine, and CINAHL were systematically searched for dual‐task studies examining older adults with SCD and analyzed using random‐effects meta‐analyses. Thirteen studies met the inclusion criteria. Within the SCD group, faster gait speed (SMD, 1.35; 95% CI, 0.57–2.13; p = .0007) and longer step length (SMD, 0.85; 95% CI, 0.44–1.26; p < .0001) favored the single compared to dual‐task condition. Faster gait speed was observed in the SCD group compared to MCI (SMD, 0.48; 95% CI, 0.28–0.67; p = .0001). A standardized dual‐task approach is needed to track gait parameters longitudinally, beginning with changes occurring at the SCD stage as these may precede future cognitive impairments.Highlights: Evidence demonstrates that SCD may be a precursor to dementia. Faster dual‐task gait speed was observed in the SCD group compared to MCI. Slower dual‐task gait speed and shorter step length were observed within the SCD group. Dual‐tasks may help differentiate between preclinical and clinical cognitive decline. Dual‐tasks should be standardized and changes should be tracked longitudinally.