Chapter 39. Nurse Staffing, Models of Care Delivery, and Interventions
(continued)
Table 39.3 Structural measures: availability of nurses and patient outcomes
(First 11 studies showed positive associations; final 5 studies detected no
significant effect)
Study Setting |
Study Design, Outcomes |
Availability of Nurses |
Effect Size (coefficient, mean differences, OR) |
1. Data were collected from 1,205 consecutively admitted patients in 40 units in 20 acute care hospitals and on 820 nurses in the
US115 |
Level 3, Level 1&3 |
0.8 mean nurse/ patient day with a range of 0.5-1.5 nurses/patient
day |
This measure was significantly associated with 30-day mortality (OR
.46, 95% CI: 0.22-0.98). An additional nurse per patient day reduces the
odds of dying by one-half. |
2. All patients who developed a central venous catheter bloodstream
infection during an infection outbreak period (January 1992 through
September 1993) and randomly selected controls. Cohort study: all SICU
patients during the study period (January 1991 through September
1993)126 |
Level 3, Level 1 |
1.2 patient/nurse and 20 nursing hours per patient day (HPPD)
1.5 patient/nurse and 16 nursing HPPD
2 patient/nurse and 12 nursing HPPD |
There was a significant relationship between nurse to patient ratios
and nursing hours and central venous catheter bloodstream infection in the
SICU. For 1.2 patients/nurse and 20 HPPD the adjusted odds ratio was 3.95
(95% CI: 1.07-14.54), 1.5 patients/nurse and 16 nursing HPPD, 15.6 (95%
CI: 1.15-211.4), and for 2 patients/nurse and 12 HPPD, 61.5 (95%
CI:1.23-3074). |
3. 39 nursing units in 11 hospitals for 10 quarters of data between
July, 1993 and December, 1995 in the US84 |
Level 3, Level 1&2 |
Proportion of direct care RN hours; total direct care hours; up to 87.5% RN skill mix |
With patient acuity controlled, direct care RN proportion of hours was
inversely associated with medication errors (-0.525 p<0. 05), decubiti
(-0.485 p<0.05), and complaints (-0.312, p<0.10). Total direct care
hours was positively associated with decubiti (0.571, p<0.10),
complaints (0.471, p<0.10), and mortality (0.491, p<0.05). A
curvilinear relationship was found so that as RN proportion increased,
rates of all adverse events decreased up to a proportion of 88% RNs. Above
that level, as RN proportion increased, the adverse outcomes
increased. |
4. 42 inpatient units in one 880-bed hospital in the US83 |
Level 3, Level 1&2 |
8.63 mean total hours of care; 69% RN skill mix; up to 85% skill mix |
With patient acuity controlled, direct care RN proportion of hours was
inversely associated with medication errors/doses (-0.576, p<0.05) and
falls (-0.456, p<0.05). Total direct care hours was positively
associated with medication errors/doses (0.497, p<0.05). A curvilinear
relationship was found so that as RN proportion increased, medication
error rates decreased up to a proportion of 85% RNs. Above that level, as
RN proportion increased, the medication error increased |
5. Data from hospital cost disclosure reports and patient discharge
abstracts from acute care hospitals in California and New York for fiscal
years 1992 and 1994125 |
Level 3, Level 1&2 |
7.56-8.43 mean total hours of care/nursing intensity weight (NIW);
67.7% to 70.5% RN skill mix |
Total hours/NIW was inversely associated with pressure ulcer rates
(-15.59, p<0.01). RN hours in California, but not New York, was
inversely associated with pneumonia (-0.39, p<0.01) Nonsignificant
association with postoperative infection rates. |
6. Data from hospital cost disclosure reports, patient discharge
abstracts and Medicare data from acute care hospitals in Arizona,
California, Florida, Massachusetts, New York, and Virginia for
1996123 |
Level 3, Level 1&2 |
5.76 mean licensed hours of care/ 83.3% RN skill mix |
Skill mix was inversely associated with pneumonia (-0.20, p<0.01),
postoperative infection (-0.38, p<0.01), pressure ulcers (-0.47,
p<0.01), and urinary tract infections (-0.61,
p<0.01). |
7. Data from hospital cost disclosure reports, patient discharge
abstracts from acute care hospitals in California, Massachusetts, and New
York for 1992 and 1994122 |
Level 3, Level 1&2 |
7.67-8.43 mean total hours of care; 67.7-70.5% skill mix |
RN hours were inversely associated with pneumonia (-0.39, p<0.01),
pressure ulcer rates (-1.23, p<0.01), and postoperative infection
(-0.47, p<0.01) but not significant for urinary tract
infections. |
8. Data from HCFA Medicare Hospital Mortality Information 1986 and the
American Hospital Association 1986 annual survey of
hospitals116 |
Level 3, Level 1 |
0.9 mean RN/ADC (average daily census); 60% skill mix |
Controlling for hospital characteristics, number of RNs/ADC was not
significantly related to adjusted 30-day mortality rate but proportion of
RNs/all nursing staff was significantly related to adjusted 30-day
mortality rate (adjusted difference between lower and upper fourth of
hospitals -2.5, 95% CI: -4.0 to -0.9) |
9. Data from the American Hospital Association 1986 annual survey of
hospitals and medical record reviews from July 1987 to June 1988 in 6
large PPOs128 |
Level 3, Level 3 |
52.2 (Texas)-67.6% (California) skill mix |
Controlling for hospital characteristics, number of RNs/ADC was not
significantly related to problem rate but proportion of RNs/all nursing
staff was significantly related to lower problem rates (California lower
rates 3.58, upper rates 2.30 p<0.0001) |
10. Data from the American Hospital Association Annual Survey of
Hospitals for 1993 and the Nationwide Inpatient Sample from the Agency for
Health Care Policy and Research for 1993 (HCUP-3)124 |
Level 3, Level 1 |
67.8% mean skill mix |
Proportion of RN FTEs/all nursing FTEs was inversely related to
thrombosis after major surgery (beta -33.22, 95% CI: -57.76 to -8.687),
urinary tract infection after surgery (beta -636.96, 95% CI: -852.78 to
-421.15), pneumonia after major surgery (beta -159.41, 95% CI: -252.67 to
-66.16), and pulmonary compromise after major surgery (beta -59.69, 95%
CI: -117.62 to 1.76). |
11. Data were collected form March 1 to June 7, 1986 and included 497
patients127 |
Level 3, Level 2 |
Adequate staffing |
The adequately staffed unit had fewer complications than the
inadequately staffed unit. |
12. 390 patients admitted within 1 week after stroke onset in 9 acute
care hospitals in The Netherlands. Surviving patients were interviewed 6
months post-stroke and asked about falls. Fall and other patient data were
collected from medical records. Ward characteristics were provided by
senior nurses. There is complete data on 349 patients89 |
Level 3, Level 2 |
0.04 mean difference in nurse to patient ratios |
There was no statistical difference in falls between case and control
groups in number of nurses or nurse ratios on any shift. Days (mean
difference -0.06, CI: -0.51 to 0.39); Evening (mean difference -0.24, 95%
CI: -0.97 to 0.50); Nights (mean difference 1.24, 95% CI: 0.28 to 2.20);
All shifts (mean difference 0.04, 95% CI, -0.33 to 0.40). |
13. 17,440 patients across 42 ICUs in the US30 |
Level 3, Level 1-3 |
Mean .66 patient/nurse with a range of 0.31-1.31 |
Neither nurse to patient ratio nor caregiver interaction was found to
be significantly associated with risk-adjusted mortality.
|
14. Data were collected from April, 1994-March, 1995 from 23 trusts
(groups of hospitals) in Scotland117 |
Level 3, Level 1 |
Mean RN FTE was 1.21 per patient |
There was no association between RN FTE per occupied hospital bed and
mortality |
15. Data were collected form the American Hospital Association Annual
Survey of Hospitals in 1989-1991, the observed and predicted 30-day
post-admission mortality for patients with a primary diagnosis of COPD
from the HCFA Hospital Information Reports from 1989-1991 and the Medicare
Case Mix Index118 |
Level 3, Level 1 |
RN FTE/100 adjusted admissions |
There was no association between RN FTE/100 adjusted admissions and
30-day post-admission mortality for patients with a primary diagnosis of
COPD |
16. Data from staffing and accounting records of 60 community hospitals
across the US in 1985, hospital and nursing unit surveys, 1981 case mix
indexes from the Federal Register, and the Health Area Resources
File129 |
Level 3, Level 3 |
52% RN skill mix; 33% LPN mean nursing HPPD was 4.93 |
None of the staffing variables of interest were associated with
medication errors, patient injuries, IV administration errors, or
treatment errors. |
Table 39.4 Structural variables: nursing organization models and patient
outcomes
Study Setting |
Study Design, Outcomes |
Organization of Care/Models |
Effect Size (coefficient, mean differences, OR) |
Data were collected from 39 "magnet" hospitals, which are hospitals
designated as good places for nurses to work, and 195 nonmagnet matched
hospitals29 |
Level 3, Level 1 |
Magnet hospitals |
Magnet hospitals had a 4.6% lower adjusted Medicare mortality rates
(p=0.026, 95% CI: 0.9-9.4 fewer deaths per 1,000) |
Data were collected form 1,205 consecutively admitted patients in 40
units in 20 acute care hospitals and on 820 nurses in the
US115 |
Level 3, Level 1&2 |
Magnet hospitals (nurse control over practice variable) |
Nurse control over practice was not significantly associated with any
clinical outcomes, but was significantly associated with patient
satisfaction (coefficient 0.56 (95% CI: 0.16-97) |
17,440 patients across 42 ICUs in the US30 |
Level 3, Level 1-3 |
Magnet hospitals (nurse unit culture captured in caregiver interaction
variable) |
Caregiver interaction was not significantly associated with clinical
outcomes, but was significantly associated with lower risk-adjusted length
of stay (-0.16, p<0.05) and lower nurse turnover (-0.21,
p<0.05) |
Data were collected at 3 points in time; 6 month before the
intervention, 6 months, and 12 months after the introduction of the new
model and included the time between October 1996 to December
199779 |
Level 3, Level 2 |
Patient Focused Care |
There was a significant reduction in medication errors between
the pre-model change (0.97%) and the post-model change (0.78%, p=0.016)
and no difference in the other measures |
Data were collected 6 months before and 6 months after the introduction
of the new model and included the time between January-June, 1992 and
January-June, 1993130 |
Level 3, Level 2 |
RN-UAP Partnership similar to Patient Focused Care |
There was a significant reduction in falls (4.7732, p< 0.05) and no
difference in the other measures between the pre- and
post-measures. |
Review article: Pierce, 1997131 |
Level 3A, Level 1&2 |
Nursing Environment |
There are mixed results in studies about whether the predictor
variables related to nurses and nursing are related to the outcomes of
interest or whether the conceptual models being used are
incomplete. |
Review article: MEDLINE® from 1966-1996, CINAHL from 1982-1996, Expanded
Academic Index from 1989-1996, search by author for investigators known to
be working in the field, manual searches of the bibliographies of review
articles and monographs (Mitchell)111 |
Level 3A, Level 1&2 |
Nursing Environment |
Mixed results in studies about whether nursing surveillance, quality of
working environment, and quality of interaction with other professionals
predict hospitals with lower mortality. With more sophisticated risk
adjustment, evidence suggests that mortality and complications are related
more to patient variables and adverse events may be more closely related
to organizational characteristics. |
Table 39.5 Process measures: nurse intervention and patient outcomes
Study Setting |
Study Design, Outcomes |
Intervention |
Effect Size (coefficient, mean differences, OR) |
Data were collected from 60 hospitalized patients on 1 surgical service
in a university hospital in Turkey between September 1996 and September
199744 |
Level 2, Level 2&3 |
Added education to intervention group |
Positive colonization of catheter hub was 68.6% in the control group
and 25% in the intervention group (chi square=5.75, p<0.05); mean
positive nurse practice scores in control group was 45.7 and 66.5 after
education (p<0.05) |
2 surgical and 2 medical wards in one hospital in Sweden were randomly
assigned to either a control or experimental group. 18 nurses on the
experimental wards and 18 nurse on the control wards; 90 patients on the
experimental wards and 39 patients on the control wards; 112 Peripheral
IVs on the experimental wards and 60 PIVs on the control
wards47 |
Level 1, Level 2&3 |
Added education to intervention group |
50% of the PIV lines in the control group had
thrombophlebitis/complications compared with 21% in intervention
(p<0.001); positive association observed for nurse practices related to
care of PIV lines was 12% in the control group and 72% in the experimental
group; there was complete nursing documentation in 10% of the control
group and 66% of the experimental group |
One hospital in Spain; all nosocomial infection data between March 1982
and December 199054 |
Level 3, Level 1 |
Added education to intervention group |
Additional training was associated with a significant 3.63% decrease (p<0.01) in nosocomial infection
rates |
One university hospital in Washington, DC; all adult patients with
bloodstream Infections between July 1984 and February 1994
(n=432)45 |
Level 3, Level 2 |
Added education |
No significant difference in total BSI rates or central line BSI rates
before, during or after the program |
One general hospital in Illinois; all omitted and wrong dose medication
errors between October 1992 and March 199343 |
Level 3, Level 2 |
Added education |
No difference in wrong dose IV medication errors for 12 months after
training; there was a decrease in omitted dose IV mediation errors for 12
months after training (p<0.01). |
All urinary catheter-patient-days between January 1995 and September
1996 in 1 VA hospital55 |
Level 3, Level 2 |
Provided infection rate data to nurses |
Pre-intervention there were 32/1000 catheter-patient days (95% CI:
22.9-43.7); for the 5 quarters post intervention, there was a significant
decrease (p<0.01) in the average infection rate (17.4/1000
catheter-patient-days (95% CI: 14.6-20.6)) compared to pre-intervention
|
Stanford University Hospital; all pressure ulcers and nosocomial
pressure ulcers during 1992 through 199657 |
Level 3, Level 2 |
Provided nosocomial pressure rate data to nurses plus added
education |
After Intervention #1, total pressure ulcer rate went from 20% to 21%;
nosocomial pressure ulcer rates went from 19% to 21%. After Intervention
#2 total pressure ulcer rates stayed at 21% but nosocomial pressure ulcer
rates went from 21% to 13%. One-year later, total pressure ulcer rates
were 10.9% and nosocomial pressure rates were 8.1%. |
8. Stanford University Hospital 52 bed medical surgical unit; all falls
between 1995 through 199656 |
Level 3, Level 2 |
Provided fall rate data to nurses and added education |
Pre-intervention the fall rate ranged from 4.2 to 3.7 fall per thousand
patient days (FPTPD); after Intervention #1 the fall rate was 5.2 FPTPD;
after Intervention #2 the fall rate ranged from 5.1 to 3.7
FPTPD. |
Return to Contents
Proceed to Next Section
|