Risk factors for mortality of residents in nursing homes with Covid-19: a retrospective cohort study
Authors: Suñer Clara , Ouchi Dan , Mas Miquel Àngel , Alarcon Rosa Lopez , Mesquida Mireia Massot , Negredo Eugènia , Prat Núria , Bonet-Simó Josep Maria , Miralles Ramon , Colet Montserrat Teixidó , Puigvendrelló Joaquim Verdaguer , Henríquez Norma , Marks Michael , Ara Jordi , Mitjà Oriol 
Published: November 2020

Background

Nursing homes have shown remarkably high Covid-19 incidence and mortality. We aimed to explore the contribution of structural factors of nursing home facilities and the surrounding district to all-cause and Covid-19-related deaths during a SARS-CoV-2 outbreak.

Methods

In this retrospective cohort study, we investigated the risk factors of Covid-19 mortality at the facility level in nursing homes in Catalonia (North-East Spain). The investigated factors included characteristics of the residents (age, gender, comorbidities, and complexity and/or advanced disease), structural features of the nursing home (total number of residents, residents who return home during the pandemic, and capacity for pandemic response, based on an ad hoc score of availability of twelve essential items for implementing preventive measures), and sociodemographic profile of the catchment district (household income, population density, and population incidence of Covid-19). Study endpoints included all-cause death and Covid-19-related death (either PCR-confirmed or clinical suspicion).

Findings

The analysis included 167 nursing homes that provide long-term care to 8,716 residents. Between March 1 and June 1, 2020, 1,629 deaths were reported in these nursing homes; 1,089 (66□9%) of them were Covid-19-confirmed. The multivariable regression showed a higher risk of death associated with a higher percentage of complex patients (HR 1□09; 95%CI 1□05-1□12 per 10% increase) or those with advanced diseases (1□13; 1□07-1□19), lower capacity for implementing preventive measures (1□08; 1□05-1□10 per 1-point increase), and districts with a higher incidence of Covid-19 (2□98; 2□53-3□50 per 1000 cases/100,000 population increase). A higher population density of the catchment area was a protective factor (0□60; 0□50-0□72 per log10 people/Km2increase).

Interpretation

Presence of residents with complex/advance disease, low capacity for pandemic response and location in areas with high incidence of Covid-19 are risk factors for Covid-19 mortality in nursing homes and may help policymakers to prioritize preventative interventions for pandemic containment.

Funding

Crowdfunding campaign YoMeCorono (https://www.yomecorono.com/), and Generalitat de Catalunya.

Research in context

Evidence before this study

We searched PubMed for studies exploring the management of Covid-19 in long-term care settings. The search was performed on May 1, 2020, and included the keywords “Covid-19”, “nursing home”, “long term care”, and “skilled nursing facility” with no language restriction. In addition to descriptive reports of Covid-19 mortality in the long-term care setting, we found studies providing evidence on the influence of age and comorbidities to mortality at the individual level. Some authors reported comparisons in the incidence and mortality of Covid-19 between facilities and country areas, and suggested the characteristics of each area/facility that may explain differences in mortality. However, we found no published works specifically investigating the contribution of structural features of the facility and sociodemographic characteristics of the area to explaining differences in Covid-19 mortality among long-term care facilities.

Added value of this study

This is the first analysis of risk of mortality at a facility level of residents with Covid-19 in nursing homes. We enrolled up to 167 nursing homes providing long-term care to 8,716 residents and we actively identified risk factors for Covid-19 mortality at the facility level. We found that nursing homes with lower capacity for pandemic response, and located in districts with a higher incidence of Covid-19 had significantly higher risks of Covid-19 mortality. The percentage of complex and/or advanced disease patients was also a risk factor.

Implications of all the available evidence

Our findings provide policymakers with critical information to prioritize long-term care facilities at higher risk when deploying preventative interventions to minimize mortality in this setting. The association between mortality within the nursing home and Covid-19 incidence in the catchment area reinforces the importance of preventing the entry of SARS-CoV-2 into facilities. Nursing homes with limited capacity to implement containment measures should be prioritized when deploying preventative interventions for minimizing Covid-19 mortality in long-term care facilities.