Patient Satisfaction and Quality of Surgical Care in U.S. Hospitals (Supplemental
Digital Content)
Supplemental Digital Content Table of Contents
Table, Supplemental Digital Content 1: Multivariate Analysis of Patient Rating and
Quality of Surgical Processes and Outcomes
Table, Supplemental Digital Content 2: Procedure-Specific Multivariate Analysis of
Patient Satisfaction and Quality of Surgical Processes and Outcomes
Table, Supplemental Digital Content 3: Multivariate Analysis of Patient Satisfaction and
Quality of Surgical Processes and Outcomes by Domains of HCAHPS Survey
Table, Supplemental Digital Content 4: Performance on HCAHPS by CMS Hospital
Case-Mix Index
Table, Supplemental Digital Content 5: Multivariate Analysis of Patient Rating and
Quality of Surgical Processes and Outcomes Adjusting for Hospital Case-Mix
Table, Supplemental Digital Content 6: Multivariate Analysis of Patient Rating and
Quality of Surgical Processes and Outcomes Adjusting for Hospital Percent of Medicare
Patients
Table, Supplemental Digital Content 7: Multivariate Hospital Random Effects Model of
Patient Rating and Quality of Surgical Processes and Outcomes
Table, Supplemental Digital Content 1: Multivariate Analysis of Patient Satisfaction and
Quality of Surgical Processes and Outcomes
Patient
Satisfaction
(Recommend
Hospital)
Patient
Satisfaction
(Hospital
Rating)
SCIP
Process
Score
RiskAdjusted
Surgical
Readmission
Rate
RiskAdjusted
Surgical
Mortality
Rate
RiskAdjusted
Surgical
Length of
Stay
Standardized
Composite
Surgical
Quality (Zscore)
0.0459738
-0.0004839
-0.0002877
-0.0304509
-0.0078821
0.0466114
-0.0004238
-0.000236
-0.0291553
-0.0073404
Five separate multivariate regression models with Surgical Care Improvement Project
(SCIP) Score, risk-adjusted surgical readmission rate, and risk-adjusted perioperative
mortality rate, risk-adjusted length of stay, and standardized composite surgical quality as
the dependent variables and patient satisfaction score as the predictor. Hospital rating
corresponds to percentage of patients that rated a hospital 9 or 10 by the HCAHPS
survey. The five models are repeated for each of the two predictors (recommend hospital
or hospital rating) of patient satisfaction. Models adjust for bed size, profit status,
teaching status, region, rural location, and percent surgical discharges. All p-values for
trend <0.001.
Table, Supplemental Digital Content 2: Procedure-Specific Multivariate Analysis of Patient Satisfaction and Quality of
Surgical Processes and Outcomes
Patient
Satisfaction
Lowest
Quartile
2nd Quartile
3rd Quartile
Highest
Quartile
CABG
Composite
Standardized
Surgical
Quality
(n=1138
hospitals)
Lobectomy
Composite
Standardized
Surgical
Quality
(n=1659
hospitals)
Hip
EVAR
AAA
Colectomy
Replacement
Composite
Composite
Composite
Composite
Standardized
Standardized
Standardized
Standardized
Surgical
Surgical
Surgical
Surgical
Quality (n=1526 Quality (n=1106 Quality (n=2824
Quality (n=2806
hospitals)
hospitals)
hospitals)
hospitals)
-0.067
-0.156
-0.134
-0.105
-0.040
-0.092
-0.119
-0.143
-0.209
-0.233
-0.183
-0.235
-0.212
-0.231
-0.139
-0.204
-0.188
-0.221
-0.200
-0.276
-0.250
-0.232
-0.256
-0.288
Results reflect six-separate multivariate regression models for each surgical procedure of interest. Quartiles of patient
satisfaction were recalculated for each model given the different sample sizes of hospitals performing each procedure type.
The dependent variable reflects a composite standardized surgical quality with equal weights for z-scores from the Surgical
Care Improvement Project (SCIP) score, risk-adjusted readmissions, risk-adjusted mortality, and risk-adjusted length of stay
measures. SCIP z-scores were inverted to match the directionality of the other measures. More negative z-scores therefore
represent higher quality. Models adjust for bed size, profit status, teaching status, region, rural location, and percent surgical
discharges. All p-values for trend <0.001. CABG=coronary artery bypass graft, EVAR=endovascular repair of abdominal
aortic aneurysm, AAA=open repair of abdominal aortic aneurysm.
Table, Supplemental Digital Content 3: Multivariate Analysis of Patient Satisfaction and
Quality of Surgical Processes and Outcomes by Domains of HCAHPS Survey
Composite
Composite
Standardized
Standardized
Surgical
Surgical
HCAHPS Domain
HCAHPS Domain
Quality
Quality
(Z-score)
Nursing Communication
(Z-score)
Adequate Pain Control
Lowest Quartile
-0.039
Lowest Quartile
-0.014
2nd Quartile
-0.113
2nd Quartile
-0.115
3rd Quartile
-0.133
3rd Quartile
-0.118
Highest Quartile
-0.159
Highest Quartile
-0.157
Physician Communication
Cleanliness of Patient Room
Lowest Quartile
-0.054
Lowest Quartile
-0.054
2nd Quartile
-0.118
2nd Quartile
-0.116
3rd Quartile
-0.126
3rd Quartile
-0.138
Highest Quartile
-0.128
Highest Quartile
-0.132
Medication Communication
Quietness of Patient Room
Lowest Quartile
-0.059
Lowest Quartile
-0.081
2nd Quartile
-0.115
2nd Quartile
-0.113
3rd Quartile
-0.108
3rd Quartile
-0.126
Highest Quartile
-0.152
Highest Quartile
-0.107
Nursing Care
Provided Discharge Instructions
Lowest Quartile
-0.048
Lowest Quartile
-0.046
2nd Quartile
-0.111
2nd Quartile
-0.095
3rd Quartile
-0.134
3rd Quartile
-0.125
Highest Quartile
-0.174
Highest Quartile
-0.160
For domain-specific analyses, ratings of “usually” or “always” were grouped together as
positive measures of the domains of patient satisfaction. Separate multivariate models
were created with each domain as the predictor of interest per model. The dependent
variable reflects a composite standardized surgical quality with equal weights for z-scores
from the Surgical Care Improvement Project (SCIP) score, risk-adjusted readmissions,
risk-adjusted mortality, and risk-adjusted length of stay measures. SCIP z-scores were
inverted to match the directionality of the other measures. More negative z-scores
therefore represent higher quality. Models adjust for bed size, profit status, teaching
status, region, rural location, and percent surgical discharges. All p-values for trend
<0.001.
Table, Supplemental Digital Content 4: Performance on HCAHPS by CMS Hospital Case-Mix
Index
Patient Satisfaction
Case-Mix Index
Lowest Quartile
1.33 [1.21, 1.47]
2nd Quartile
1.40 [1.25, 1.57]
3rd Quartile
1.52 [1.36, 1.67]
Highest Quartile
1.60 [1.41, 1.78]
HCAHPS = Hospital Consumer Assessment of Healthcare Providers and Systems; CMS =
Centers for Medicare and Medicaid Services
Table, Supplemental Digital Content 5: Multivariate Analysis of Patient Rating and Quality of Surgical Processes and Outcomes Adjusting
for Hospital Case-Mix
Bivariate
Composite
Standardized
Surgical Quality
Score
P-Value
Multivariate
Composite
Standardized
Surgical Quality
Score
P-Value
Multivariate CaseMix Adjusted
Composite
Standardized
Surgical Quality
Score
P-Value
Patient Satisfaction
Lowest Quartile
0.039
2nd Quartile
-0.048
-0.010
0.013
-0.079
<0.001
-0.064
<0.001
<0.001
3rd Quartile
-0.103
-0.105
-0.105
Highest Quartile
-0.177
-0.145
-0.159
The dependent variable reflects a composite standardized surgical quality with equal weights for z-scores from the Surgical Care
Improvement Project (SCIP) surgical score, risk-adjusted readmissions, risk-adjusted mortality, and risk-adjusted length of stay measures.
SCIP z-scores were inverted to match the directionality of the other measures; therefore, more negative z-scores represent higher surgical
quality. Multivariate models adjust for bed size, profit status, teaching status, region, rural location, and percent surgical discharges. The
case-mix adjusted model further adjusts for hospital case-mix using the Medicare case-mix index (CMI). All regressions weighted by
hospital procedure volume.
Table, Supplemental Digital Content 4: Multivariate Analysis of Patient Rating and Quality of Surgical Processes and Outcomes Adjusting
for Hospital Percent of Medicare Patients
Bivariate
Composite
Standardized
Surgical Quality
Score
P-Value
Multivariate
Composite
Standardized
Surgical Quality
Score
P-Value
Multivariate
Composite
Standardized
Surgical Quality
Score, Adjusted
for Percent
Medicare
P-Value
Patient Satisfaction
Lowest Quartile
0.039
2nd Quartile
-0.048
-0.010
0.014
-0.079
<0.001
-0.066
<0.001
<0.001
3rd Quartile
-0.103
-0.105
-0.103
Highest Quartile
-0.177
-0.145
-0.160
The dependent variable reflects a composite standardized surgical quality with equal weights for z-scores from the Surgical Care
Improvement Project (SCIP) surgical score, risk-adjusted readmissions, risk-adjusted mortality, and risk-adjusted length of stay measures.
SCIP z-scores were inverted to match the directionality of the other measures; therefore, more negative z-scores represent higher surgical
quality. Multivariate models adjust for bed size, profit status, teaching status, region, rural location, and percent surgical discharges. All
regressions weighted by hospital procedure volume.
Table, Supplemental Digital Content 6: Multivariate Hospital Random Effects Model of Patient Rating and Quality of Surgical Processes and
Outcomes
Multivariate
Adjusted Surgical
Readmission Rate:
Random Effects
Model
Patient Satisfaction
Lowest Quartile
2nd Quartile
3rd Quartile
Highest Quartile
13.8%
13.1%
12.5%
12.2%
P-Value
Multivariate
Adjusted Surgical
Mortality Rate:
Random Effects
Model
<0.001
3.6%
3.3%
3.2%
2.8%
P-Value
Multivariate
Adjusted Surgical
LOS: Random
Effects Model
P-Value
<0.001
7.8
7.4
7.2
7.1
<0.001
Random effects models adjust for patient age, sex, comorbidities, and procedure type as well as hospital features including bed size, profit
status, teaching status, region, rural location, and percent surgical discharges. Unit of analysis is at the level of the patient.