No abstract

Free‐ranging groups are frequently assorted by phenotypic characters. However, very little is known about the underlying processes that determine this structuring. In this study, we investigate the mechanisms underlying the phenotypic composition of shoals of guppies (Poecilia reticulata) in a high‐predation stream in Trinidad's Northern Mountain Range. We collected 57 entire wild shoals, which were strongly assorted by body length. Shoal encounters staged within an experimental arena showed shoal fission (but not fusion) events to be an important mechanism in generating phenotypic assortment. In the wild, fission and fusion between guppy shoals occurred extremely frequently and thus are unlikely to constrain the opportunities for shoal assortment. However, fission and fusion processes occur under the restrictions imposed by the distribution of individuals within the environment. We observed size specific segregation within the habitat in three dimensions, providing a passive mechanism that contributes to the maintenance of the observed homogeneity of group composition. Furthermore sex differences were found in social behaviour. Individual male guppies switched between shoals more frequently than females and left a shoal more often than females. We argue that shoal composition is determined by habitat segregation on a medium spatial scale and by fission/fusion processes on a small spatial scale (with sex‐specific shoal dynamics adding a additional layer of complexity).

OBJECTIVES To examine the relationship between registered nurse (RN) burnout, job dissatisfaction, and missed care in nursing homes. DESIGN Cross‐sectional secondary analysis of linked data from the 2015 RN4CAST‐US nurse survey and LTCfocus. SETTING A total of 540 Medicare‐ and Medicaid‐certified nursing homes in California, Florida, New Jersey, and Pennsylvania. PARTICIPANTS A total of 687 direct care RNs. MEASUREMENTS Emotional Exhaustion subscale of the Maslach Burnout Inventory, job dissatisfaction, and missed care. RESULTS Across all RNs, 30% exhibited high levels of burnout, 31% were dissatisfied with their job, and 72% reported missing one or more necessary care tasks on their last shift due to lack of time or resources. One in five RNs reported frequently being unable to complete necessary patient care. Controlling for RN and nursing home characteristics, RNs with burnout were five times more likely to leave necessary care undone (odds ratio [OR] = 4.97; 95% confidence interval [CI] = 2.56‐9.66) than RNs without burnout. RNs who were dissatisfied were 2.6 times more likely to leave necessary care undone (OR = 2.56; 95% CI = 1.68‐3.91) than RNs who were satisfied. Tasks most often left undone were comforting/talking with patients, providing adequate patient surveillance, patient/family teaching, and care planning. CONCLUSION Missed nursing care due to inadequate time or resources is common in nursing homes and is associated with RN burnout and job dissatisfaction. Improved work environments with sufficient staff hold promise for improving care and nurse retention. J Am Geriatr Soc 67:2065–2071, 2019

The coronavirus disease 2019 (COVID-19) pandemic has severely affected nursing homes. Vulnerable nursing home residents are at high risk for adverse outcomes, but improved understanding is needed to identify risk factors for mortality among nursing home residents. OBJECTIVE To identify risk factors for 30-day all-cause mortality among US nursing home residents with COVID-19. DESIGN, SETTING, AND PARTICIPANTS This cohort study was conducted at 351 US nursing homes among 5256 nursing home residents with COVID-19-related symptoms who had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction testing between March 16 and September 15, 2020. EXPOSURES Resident-level characteristics, including age, sex, race/ethnicity, symptoms, chronic conditions, and physical and cognitive function. MAIN OUTCOMES AND MEASURES Death due to any cause within 30 days of the first positive SARS-CoV-2 test result. RESULTS The study included 5256 nursing home residents (3185 women [61%]; median age, 79 years [interquartile range, 69-88 years]; and 3741 White residents [71%], 909 Black residents [17%], and 586 individuals of other races/ethnicities [11%]) with COVID-19.Compared with residents aged 75 to 79 years, the odds of death were 1.46 (95% CI, 1.14-1.86) times higher for residents aged 80 to 84 years, 1.59 (95% CI, 1.25-2.03) times higher for residents aged 85 to 89 years, and 2.14 (95% CI, 1.70-2.69) times higher for residents aged 90 years or older. Women had lower risk for 30-day mortality than men (odds ratio [OR], 0.69 [95% CI, 0.60-0.80]). Two comorbidities were associated with mortality: diabetes (OR, 1.21 [95% CI, 1.05-1.40]) and chronic kidney disease (OR, 1.33 [95%,). Fever (OR, 1.66 [95% CI,), shortness of breath (OR, 2.52 [95% CI, 2.00-3.16]), tachycardia (OR, 1.31 [95% CI,), and hypoxia (OR, 2.05 [95% CI, 1.68-2.50]) were also associated with increased risk of 30-day mortality. Compared with cognitively intact residents, the odds of death among residents with moderate cognitive impairment were 2.09 (95% CI, 1.68-2.59) times higher, and the odds of death among residents with severe cognitive impairment were 2.79 (95% CI, 2.14-3.66) times higher. Compared with residents with no or limited impairment in physical function, the odds of death among residents with moderate impairment were 1.49 (95% CI, 1.18-1.88) times higher, and the odds of death among residents with severe impairment were 1.64 (95% CI, 1.30-2.08) times higher. CONCLUSIONS AND RELEVANCEIn this cohort study of US nursing home residents with COVID-19, increased age, male sex, and impaired cognitive and physical function were independently associated with mortality. Understanding these risk factors can aid in the development of clinical prediction models of mortality in this population.