Special Report: Infection Control and Managed Care

Canadian BSI study finds rate rise after restructuring

Hemodialysis BSIs linked to shift in care delivery

Researchers in Canada have linked health care delivery changes similar to those occurring under managed care in the United States to an increase in bloodstream infections (BSIs) in hemodialysis patients, the lead author of the study reports.

While Canada operates under a system of socialized medicine, recent health care delivery changes in the country are generally reflective of the managed care phenomenon in the United States, says Geoffrey Taylor, MD, professor of medicine and infection control officer at the University of Alberta Hospital in Edmonton.

"I think we are seeing some similar things," he tells Hospital Infection Control. "If I understand managed care, it takes a population of patients and treats them in a cost-efficient kind of way by maximizing outpatient delivery and minimizing inpatient delivery — keeping hospitals for the most seriously ill conditions. I think that is what has happened to us. The difference is that our managed care population is the entire population of our province because it is a public system. But that is what the insurer — which in our case is the government — decided to do with our health care system."

In the study, Taylor and co-authors reported an abrupt rise in hemodialysis infection rate in the unit that coincided with use of central venous catheters (CVCs) as a means of vascular access.¹ The hemodialysis bacteremia rate more than doubled, from 1.2 per 1,000 runs in 1995 to 2.8 per 1,000 in the first six months of 1996.

"The increase in CVC use occurred shortly after major restructuring and downsizing of the publicly funded health care system had occurred in our region, including a 35% reduction in hospital beds over a one-year period," they concluded. ". . . Entry into the hemodialysis program in the region was consolidated to our unit, where hemodialysis often commenced through a temporary CVC access while awaiting creation of a surgical graft or fistula. However, surgical time for creation of a graft or fistula was not increased, and the relative proportion of patients undergoing hemodialysis in the unit through a CVC consequently increased, reaching more than 40% of the unit population."

Infection rates have been shown to be higher when CVCs are used for hemodialysis, but the changes in the health care system made it more difficult to provide long-term access through grafts or fistulas created surgically, they noted. "The rise in hemodialysis-related bacteremia in our unit is attributable to increased use of CVCs for vascular access, which in turn was due to changes in health care delivery in our region that have resulted in delays in creation of vascular grafts for hemodialysis access," the authors concluded.

However, no such direct causal relationship could be found in a related study of intensive care patients, and findings were unclear for non-ICU patients even though BSIs in both groups increased, Taylor reported in additional data presented in San Diego at the recent Interscience Conference on Antimicrobial Agents and Chemotherapy.^2,3

Fewer bed days, more infections

Prospective monitoring of nosocomial bloodstream infections (NBSIs) over a 10-year period revealed a sharp increase in infection rates following the health care restructuring in 1995 that generally resulted in more severely ill patients under hospital care, he reports. The NBSI rate per 1,000 admissions rose progressively from 6.0 in 1986 to 11.2 in 1996. However, 48% of the total increase occurred between 1995 and 1996 following the health care restructuring.

"There was a decrease in bed numbers, admissions, and patient days by 10% to 20%," Taylor explained. "We downsized in that sense, and achieved the economic goals of reducing the beds. What we concomitantly did was increase our absolute and relative proportion of surgical patients, intensive care patients particularly, and eliminated low-intensity patients — obstetrics patients, medical patients, pediatric patients — whose care was relegated to a community setting."

Overall, the hospital restructuring was associated with a 30% increase in NBSI number and a 61% increase in NBSI rate.

"What had in effect happened is that our patients had become on average much sicker and much more commonly exposed to invasive procedures," Taylor says. "As we would expect, the infection rates did indeed go up. It was a global increase. Both primary and secondary infections increased. In fact, the infection rate in non-ICU patients increased more than ICU patients, indicating that the increase in infections was widespread throughout the entire institution [and] not focal to just ICU patients or a certain ward."

A closer look revealed there was no increase in the BSI rate in the ICU patients per 1,000 catheter days, he explained.

"What was going on in the ICUs was that they were using more central venous catheters — probably because the patients were sicker — but the per CVC infection rate did not change," Taylor says.

However, the increase in the non-ICU area was explained less easily because there were ongoing shifts in nursing ratios and skill mix. For example, shifts in staffing resulted in more use of licensed practical nurses rather than registered nurses.

"[Hemodialysis] was the one area where we were able to document some change in the overall risk-adjusted infection rate, whereas in the ICUs we could not," he said. "An unanswered question, and one that I am still struggling with, is what about the general care on wards, where there were changes in the nurse-patient [ratios]?"

However, that severity of illness probably also increased in the non-ICU patients, who are more likely under health care delivery changes to have invasive devices in place or have had surgery rather than simply convalescing from an illness, he adds. With the exception of the clearly identified trend in hemodialysis patients, the BSI increase could not be easily explained by reduced quality of care due to health care restructuring.

"Has the quality of care changed?" Taylor asks. "That is the million-dollar question. . . . We don’t have any evidence that the quality of care overall has deteriorated, though we did find this one area in dialysis. It is one that we need to continually watch, and I believe that infection rates are quite a good measure of quality of care and should be used that way."

References

1. Taylor GD, McKenzie M, Buchanan-Chell M, et al. Central venous catheters as a source of hemodialysis-related bacteremia. Infect Control Hosp Epidemiol 1998; 19:643-646.

2. Taylor G. Nosocomial bloodstream infections (NBSI): Ten year trends in one institution. Abstract K-60. Presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). San Diego; Sept. 24-27, 1998.

3. Taylor G, McKenzie M, Kirkland M, et al. Nosocomial blood stream infections (NBSI) in restructured hospital. Abstract K-63. Presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). San Diego; Sept. 24-27, 1998.