Title: Hierarchical analysis of the impact of hospital characteristics on mortality in Alberta hospitals
1Hierarchical analysis of the impact of hospital
characteristics on mortality in Alberta
hospitals
- Carole A. Estabrooks, RN, PhD
- William K. Midodzi, MSc
- Greta G. Cummings, RN, PhD(c)
- Kathryn L. Ricker, MSc
- Phyllis Giovannetti, RN, ScD
Sigma Theta Tau International November, 2003
2Financial Support
Project Funding
- Alberta Heritage Foundation for Medical Research
Career support
- Canadian Institutes of Health Research (CIHR)
- Alberta Heritage Foundation for Medical Research
3International Study of Hospital Outcomes
i n t r o d u c t i o n
- Purpose
- To determine the effects of the organization and
nurse staffing of hospitals on patient and nurse
outcomes.
4Motivation for Research Agenda
- Widespread hospital restructuring and work
redesign - Changing hospital staffing patterns
- Absence of empirical evidence of these changes on
outcomes
5International samples
sample
Hospitals Nurses Alberta 109
6,526 British Columbia 97 2,838 England 32
5,006 Germany 30 4,000 Ontario 209 8,778
Scotland 7 5,238 U.S. (PA) 210
14,145
6Alberta
sample
Hospitals Nurses 109 6,526 49
4,799 Criteria 5 nurses at least 20
beds
7Sample Characteristics
Sample
(49 hospital) Population (109
hospital) Regular (FT/PT)
35.1/58.9
34.2/60.1 Casual
19.0
18.7 Female
97.2
97.5 Male
2.5
2.5 Age, yrs
40.4
40.9 Hours /wk 0-30
50.9
52.0 30 or more
46.5
45.5 Shift 8 Hrs
52.6
55.6 12 Hrs
35.8
33.8
Mixed 7.4
6.8 Diploma
(RN) 77.2
77.4 Baccalaureate
22.5
22.1
8Data Sources
data sources
-
- Nurse survey
- Administrative data
- Alberta CIHI Hospital Inpatient Database
- Alberta Health Care Insurance Plan Registry
- Characteristics of Alberta acute care hospitals
-
9The Alberta Nurse Survey
- Census of all staff nurses in hospitals
(N12,345) - Useable returns 6526 (52.8)
A Employment Characteristics B Nursing
Work Index (NWI) C Maslach Burnout
Inventory(MBI) D Job characteristics E
Last shift F Demographics G Site specific
questions
10The Model
Organization Nurse Patient
1130-day mortality model
Ability to develop relationships/Continuity of
care
Nursing training and skill variables
Quality of work environment
- Patient's characteristics
- Age
- Sex
- Co morbidity factors
- Complication
- Chronicity
30-day mortality
Other unknown determinants at the patient and
hospital levels
- Institutional factors
- Bed size
- Teaching hospital status
- Hospital location
- Hi-technology facility
12Conceptual Basis for Hierarchical Modeling
Z
Level 2 (Hospital Level)
Level 1 (Patient Level)
X
Y
X Individual patient characteristics (age, sex,
admission diagnoses, comorbidity factors,
in-hospital complications, etc. ) Z Hospital
characteristics (bed size, location, teaching
status, nursing and physician factors, staffing,
etc.) Y The probability (or risk) of dying
within 30 days of admission to hospital
13Nursing variables analyzed at the hospital level
- Nursing training and skill variables
- Nurse education level ( baccalaureate degree)
- Skill mix,
- Ability to develop a relationship with patients
- Job status casual or temporary staffs
- Perception of quality care
- Staffing, patients per nurse
- Patients care needs unattended
- Non-nursing activities performed by nurses
- Quality of work environment
- Nurse job satisfaction
- Support for non-floating policy
- Nurse autonomy
- Nurse-physician relationships
- Emotional abuse
-
14Inter-hospital variation in risk adjusted 30-day
mortality
High mortality 16 hospitals
Low mortality 16 hospital
Average mortality 17 hospitals
Average co-morbidity score 0.0752
Average co-morbidity score 0.0725
Average co-morbidity score 0.0726
15Nursing characteristics of study hospitals
16The Linear Hierarchical Models(Outcome Risk
adjusted 30-day mortality)
- Model 1 (Patient Level) Controlling for patient
factors - Age, years
- Sex (Male/Female)
17The Linear Hierarchical Models(Outcome Risk
adjusted 30-day mortality)
- Model 1 (Patient Level) Controlling for patient
factors - Age, years
- Sex (Male/Female)
- Model 2 (Hospital level) Institutional
characteristics - Bed size ( lt50, 51-150, gt150)
- Teaching status (gt1 resident per 4 bed, lt1
residence per 4 bed, none) - Location of hospitals (small cities pop. lt50K
large cities pop. gt50K)
18The Linear Hierarchical Models(Outcome Risk
adjusted 30-day mortality)
- Model 1 (Patient Level) Controlling for patient
factors - Age, years
- Gender (Male/Female)
- Model 2 (Hospital level) Instructional
characteristics - Bed size
- Teaching status Location of hospitals
- Model 3 (Hospital Level) Nursing related
hospital characteristics - Nurse education level
- Skill mix
- Job status casual or temporary
- Perception of quality care
- Staffing ratio last shift
- Patients care needs unattended
- Non-nursing activities performed by nurses
- Job satisfaction
- Support for non-floating policy
- Nurse autonomy
- Nurse-physician relationships
- Emotional abuse
19Effect of nursing related hospital
characteristics
Constant - 5.19 - 0.50 x Nurse education
level - 0.27 x Skill Mix (RN to total nurse
staffs) 1.01 x Casual or temporary staffs -
0.14 x Perception of quality of care 0.01
x Staffing, pts. Per nurse ratio 0.08 x
Patients care needs unattended 0.04 x
Non-nursing activity performed - 0.12 x Job
satisfaction problems - 0.06 x Support for
non-floating policy - 0.22 x Nurse
autonomy - 0.11 x Nurse-physician
relationship 0.17 x Emotional
abuse Variance in 30-day mortality among
hospitals explained independently by
nursing-derived factors 33.1
Model adjusted for pts co-morbidity factors,
demographic variables and institutional factors
20Percent of inter-hospital variation in30-day
mortality explained by each factors
Unknown determinants
Patients co-morbidity factors
Nursing-derived variables
Patients demographic variables
Institutional factors
21Limitations
- Administrative data
- Aggregation
- Generalizability
22Summary
- Lower patient mortality across hospitals was
predicted in our models by
- higher nurse education levels
- work satisfaction
- quality of care
- support for non-floating policies
- nurse autonomy
- better nurse-physician relationships
- richer skill mix of nursing
23Summary
Patients from hospitals with higher scores on the
following had significantly greater risk of dying
within 30-days of admission
- Higher percentage of casual employment
- Higher numbers of unmet patient care needs
- More non-nursing tasks completed
- Higher levels of reported emotional abuse
- Higher patient-to-nurse ratios
24Implications