Crowded nursing homes may fuel larger, deadlier COVID outbreaks

Nov. 11, 2020

The COVID-19 death rate in less-crowded nursing homes in Ontario, Canada, was less than half that of homes with shared bedrooms and bathrooms during the first months of the pandemic, according to a study published yesterday in JAMA Internal Medicine, reported the Center for Infectious Disease Research and Policy (CIDRAP) News.

The findings come as US nursing homes are seeing a spike in new COVID-19 cases amid increasing community spread, including a 120 percent rise in Midwestern states since mid-September, according to an updated report today from the American Health Care Association/National Center for Assisted Living (AHCA/NCAL). 

New weekly nursing home cases grew 43 percent from mid-September to the week of October 18, with 1,192 nursing home deaths reported that week, according to AHCA/NCAL.

Led by researchers at Public Health Ontario, the JAMA study involved 618 Ontario nursing homes with 78,607 residents from Mar 29 to May 20. Less-crowded nursing homes reported COVID-19 death rates of 1.3 percent (578 of 46,028 residents), compared with 2.7 percent (874/32,579 residents) in more crowded homes. Of the 78,607 residents, 5,218 (6.6 percent) were infected with COVID-19, and 1,452 (1.8 percent) died. The case-fatality rate was 27.8 percent (1,452/5,218).

The vast majority of infections (4,496 [86 percent]) occurred in 63 homes (10 percent). Of the 618 nursing homes, 308 (50 percent) with mainly or only rooms housing two to four residents were considered crowded; in these settings, the coronavirus infection rate was 9.7 percent, versus 4.5 percent in homes with primarily single-occupancy rooms.

The probability of introduction of COVID-19 into the homes did not differ according to crowding level, with 31.3 percent in crowded homes and 30.2 percent in less-crowded facilities. But outbreaks tended to be larger in crowded nursing homes, with nine outbreaks involving more than 100 residents in crowded nursing homes, versus only one in less-crowded facilities.

After adjusting for region, facility, and resident variables, crowding was still tied to increased likelihood of coronavirus infection (relative risk [RR], 1.73) and death (RR, 1.69). Propensity score analysis generated comparable results for infection (RR, 2.09) and death (RR, 1.83).

Study models suggested that converting all quadruple-occupancy rooms to double occupancy could have prevented 998 COVID-19 infections (19.1 percent) and 263 deaths (18.1 percent). And had all multiple-occupancy rooms been converted to single occupancy, about 1,641 infections (31.4 percent) and 437 deaths (30.1 percent) could have been averted. For-profit ownership of nursing homes was tied to crowding and lower staffing ratios than other facilities. 

In Ontario, while older adults prefer single-occupancy rooms to shared rooms by a margin of 20 to 1, over 60 percent of residents share rooms. Residents in quadruple-occupancy rooms pay about $1,900 a month over the standard $4,200 Canadian government payment, versus $2,700 for single-occupancy rooms.

The researchers noted studies finding that 66 percent to 81 percent of coronavirus deaths in Canada occurred in nursing home residents. The increased risk is likely due to a combination of resident advanced age and underlying illnesses, congregate living, close contact with staff, and problems physical distancing from other residents due to cognitive or other types of decline.

An August study of the same nursing homes in Ontario by the same researchers found that for-profit facilities had higher rates of COVID-19 infections and deaths than their nonprofit and municipal counterparts, likely because most for-profit homes were built to older design standards that allowed quadruple-occupancy rooms. Design standards since 1999 allow no more than two beds per room.

The authors said in yesterday's study that high-occupancy resident rooms can affect a nursing home as a whole because occupants of shared rooms may come into contact with both residents of single-occupancy rooms in common areas and healthcare workers who care for lower-risk residents. "Further, our results suggest that cohorting may be ineffective in crowded homes with many shared rooms, as has been noted by nursing home administrators in Ontario," they wrote.

As a result of the early communication of the study findings, maximum occupancy in Ontario nursing homes was capped at two on June 10. "Additional measures, such as retrofitting of underoccupied hotels to act as temporary nursing homes and rapid structural adaptations to homes that are overly crowded, could be considered," the authors said.

CIDRAP has the report

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