Statistics discussion quick question
Read the
paper by Werre, Boucher, Beachey
carefully to answer the following questions:
State the dependent variables and independent variables considered in the study.
Identify and share the percentage of patients who were readmitted 30 days post discharge after receiving protocol RT?
Discuss the factors that you found to be critical in determining the length of the hospital stay.
Comparison of Therapist-Directed and Physician-Directed Respiratory
Care in COPD Subjects With Acute Pneumonia
Nicholas D Werre MSRT RRT, Erin L Boucher MSRT RRT, and
Will D Beachey PhD RRT FAARC
BACKGROUND: The purpose of this retrospective medical record review was to compare the
effects of therapist-directed (protocol RT) and physician-directed (non-protocol RT) respiratory
therapy on hospital stay and 30-d post-discharge readmission in COPD subjects with acute bacterial
pneumonia. METHODS: We reviewed 320 medical records; 244 records were usable. Information
gathered included gender, age, RT protocol type (protocol RT or non-protocol RT), hospital stay,
30-d post-discharge readmission, and disease severity score. A 3-way analysis of variance and post
hoc analysis were performed to determine the possible effects of disease severity, age, and RT
protocol type on hospital stay and the possible interaction effects among these independent variables. A chi-square test for independence was computed to determine whether there was an association between RT protocol type and 30-d readmission. RESULTS: There were no significant
interaction effects among RT protocol type, age, and disease severity on hospital stay. In addition,
there were no significant effects of either RT protocol type (P ⴝ .41) or age (P ⴝ .85) on hospital
stay in our subject sample. However, as expected, disease severity had a significant effect on hospital
stay, increasing it by a mean of 2.6 d (95% CI 0.77– 4.4, P ⴝ .005). The chi-square test for
independence revealed that the frequency of 30-d readmission was significantly associated with RT
protocol type (P ⴝ .02); fewer 30-d readmissions were associated with protocol RT. CONCLUSIONS:
We interpreted the finding of no difference in mean hospital stay between protocol and nonprotocol RT to indicate that protocol RT did not confer a disadvantage to subjects in terms of
hospital stay. Additionally, the results suggest that treatment efficacy is not sacrificed when RT is
directed by respiratory therapists rather than by physicians regardless of disease severity and that
therapist-directed protocols may have been of some benefit in reducing 30-d post-discharge readmission. Key words: respiratory therapy; COPD; patient readmission; patient discharge; stay; severity
of illness index. [Respir Care 2015;60(2):151–154. © 2015 Daedalus Enterprises]
Introduction
Respiratory therapy (RT) protocols are based on published evidence-based clinical practice guidelines. Proto-
Mr Werre is affiliated with the Respiratory Care Department, Jamestown
Regional Medical Center, Jamestown, North Dakota; Ms Boucher is
affiliated with the Respiratory Care Department, St Alexius Medical
Center, Bismarck, North Dakota; Dr Beachey is affiliated with the Respiratory Therapy Program, University of Mary/St Alexius Medical Center, Bismarck, North Dakota.
cols help standardize patient care and give respiratory therapists the ability to deliver timely care without waiting for
an order from a physician. Our institution subscribes to the
American Association for Respiratory Care’s definition of
therapist-implemented protocols1. Physicians at our hospital have the option to order RT per protocol or to order
and direct the course of RT themselves. When physicians
order RT by protocol, respiratory therapists interview and
Supplementary material related to this paper is available at http://
www.rcjournal.com.
Correspondence: Will D Beachey PhD RRT FAARC, Respiratory Therapy Program, St Alexius Medical Center/University of Mary, 900 East
Broadway, Bismarck, ND 58502. E-mail: wbeachey@primecare.org.
The authors have disclosed no conflicts of interest.
DOI: 10.4187/respcare.03208
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RESPIRATORY THERAPIST- VS PHYSICIAN-DIRECTED CARE IN COPD SUBJECTS
assess the patient, determine the most appropriate RT treatment plan, write orders, implement therapy per protocol,
monitor treatment effectiveness, and adjust, discontinue,
or restart treatment, keeping the physician informed at all
times.
SEE THE RELATED EDITORIAL ON PAGE 304
A number of studies in various health-care disciplines
have compared therapist-directed RT (protocol RT) with
physician-directed RT (non-protocol RT). Several studies
have failed to show a significant difference in subject outcomes between protocol and non-protocol RT.2,3 However, Hermeto et al4 found that protocol RT in the neonatal
ICU significantly reduced weaning time in mechanically
ventilated neonates compared with non-protocol RT.
Similarly, protocol RT was found to reduce the duration of
mechanical ventilation in adult subjects.5,6 Protocol RT
has also been credited with reducing ICU readmission secondary to atelectasis, mucus plugging, and respiratory
distress.
Therapist-directed protocols have been associated with
significant cost savings to patients and hospitals4,7,8 and
have been shown to improve overall hospital resource utilization.7-9 Kollef et al7 demonstrated that protocol RT
reduces the number of unnecessary treatments given, significantly lowering health-care costs without increasing
adverse patient outcomes. Pikarsky et al10 showed that
protocol RT reduces medication errors by eliminating variations in practice. Importantly, protocol RT results in more
timely therapy than non-protocol RT.11
This study addresses the effectiveness of protocol RT in
COPD subjects admitted for exacerbations of their disease. Although Tramacere et al11 studied the effectiveness
of therapist-directed protocols in COPD in-patients, they
focused on pulmonary rehabilitation outcomes. To our
knowledge, this is the first study that compares hospital
stay and 30-d readmission in COPD subjects with acute
pneumonia receiving protocol RT versus non-protocol RT.
Our research questions were: (1) does therapy protocol
type (therapist-directed or physician-directed) affect patient stay? (2) Does COPD severity and/or age influence
the protocol type’s effect on hospital stay? (3) Is 30-d
patient readmission associated with therapy protocol type?
QUICK LOOK
Current knowledge
Respiratory therapy (RT) protocols are based on published evidence-based clinical practice guidelines. Protocols have been shown to standardize patient care and
allow respiratory therapists to deliver appropriate, timely
care without waiting for a physician order.
What this paper contributes to our knowledge
Respiratory care delivered by respiratory therapistdriven protocols did not confer a disadvantage to subjects in terms of hospital stay compared with physiciandirected treatment. Treatment efficacy was not sacrificed
regardless of disease severity, and 30-d post-discharge
readmission rates were lower under respiratory therapistdriven protocols.
After gaining approval from our institution’s institutional review board, we conducted a retrospective medical
record review of subjects with COPD who were hospitalized between 2007 and 2012 with the diagnosis of acute
bacterial pneumonia. The following ICD-9 (International
Classification of Diseases, 9th Revision) codes were used
to identify subjects: 481, 482 and subsets, 483 and subsets,
491.21, and 496. The medical record search was designed
to exclude mechanically ventilated patients and patients
who were transferred to the transitional care or rehabilitation unit; a total of 320 medical records were identified.
Information gathered included gender, age, RT treatment status (protocol RT vs non-protocol RT), hospital
stay, 30-d readmission (yes or no), and a severity of illness
index. Thirty-day readmission was determined by manually checking discharge and readmission dates. RT treatment status was ascertained by knowledge of the ordering
physician’s identity. (At our institution, physicians either
subscribe or do not subscribe to RT protocols; a list of
subscribing and non-subscribing physicians is kept in the
hospital’s respiratory care department. For pertinent sections of our adult RT protocol, see the supplementary materials at http://www.rcjournal.com.) Of the 320 records
identified, only 245 had complete data sets. One subject’s
record was removed as an extreme outlier. Of the 244
remaining subjects, 162 (66%) received protocol RT, and
82 (34%) received non-protocol RT. We used a univariate
3-way analysis of variance (protocol type ⫻ age ⫻ COPD
severity) with pairwise post hoc comparisons and a chisquare test of independence to answer our research
questions.
The COPD severity of illness index is an integral component of the All Patient Refined Diagnosis-Related
Group system, which classifies patients according to the
chief complaint on admission, severity of illness, and risk
of mortality.12 The assigned severity of illness or risk of
mortality subclass is dependent on the patient’s underlying
problem and the number of coexisting serious diseases or
illnesses present; that is, severity of illness and risk of
mortality assignments depend on a patient’s comorbidities,
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age, principal diagnosis, and medical procedures performed. High severity of illness and risk of mortality levels are associated with multiple comorbidities and their
interactions. Four severity of illness and risk of mortality
categories numbered sequentially from 1 to 4 indicate minor, moderate, major, and extreme severity of illness and
risk of mortality, respectively.
To ensure an adequate number of cases in each category, we combined disease severity scores to create a dichotomous variable; subjects with severity scores of 1 and
2 formed one group, and subjects with scores of 3 and 4
formed a second group. The same method was used to
group subjects into 2 age categories: ⱕ 70 y and ⱖ 71 y.
Eighty-nine subjects were ⱕ 70 y old and 155 subjects
were ⱖ 71 y old.
Results
There were no significant interaction effects among the
independent variables (protocol, age, and disease severity)
on hospital stay. In addition, there were no significant
effects of protocol type (P ⫽ .41) or age (P ⫽ .85) on
hospital stay in our subject sample. The absolute nonsignificant difference for protocol on hospital stay was a
mean of 0.76 d (95% CI 1.06 –2.58), and the absolute
nonsignificant difference for age on hospital stay was a
mean of 0.175 d (95% CI 1.65–1.2). As expected, there
was a significant effect of disease severity on hospital stay
(P ⫽ .005). The absolute significant difference for the
effect of disease severity on hospital stay was a mean of
2.59 d (95% CI 0.77– 4.41).
A chi-square test for independence was performed to
determine whether readmission to the hospital within 30 d
of discharge was independent of respiratory care protocol
type. Protocol RT was significantly associated with fewer
30-d readmissions (P ⫽ .02) compared with non-protocol
RT. A total of 213 subjects avoided hospital readmission
in the first 30 d following discharge; of these subjects, 147
(69%) received protocol RT, and 66 (31%) received nonprotocol RT.
Of the 162 subjects receiving protocol RT, 15 were
readmitted within 30 d of discharge, for a readmission rate
of 9.3%. Of the 82 subjects receiving non-protocol RT,
16 were readmitted within 30 d, for a readmission rate of
19.5%.
Discussion
however, in this study, the type of RT delivery did not
affect hospital stay. There were also no significant interaction effects between protocol type and COPD severity;
that is, regardless of severity level, the protocol type did
not affect hospital stay. As expected, greater disease severity significantly affected hospital stay. Overall, the results show that regardless of disease severity, treatment
efficacy was not sacrificed when RT was directed by respiratory therapists rather than by physicians.
In this study, 30-d readmission frequency was not independent of protocol type. Only 9.3% of COPD subjects
experiencing acute pneumonias were readmitted if they
were placed on protocol RT, whereas 19.5% of subjects
given non-protocol RT were readmitted within 30 d. However, the majority of subjects in our sample (162 of 244
subjects) received protocol RT; caution must be used in
attributing the lower 30-d readmission rate to protocol RT
use. However, because the absolute number of subjects
readmitted in the smaller physician-directed RT group was
greater than the absolute number readmitted in the much
larger therapist-directed RT group (16 vs 15 readmissions,
respectively), it is reasonable to speculate that protocol RT
may have had a beneficial effect on subject readmission
rates. One wonders if the subjects receiving physiciandirected RT had more severe disease than the subjects
receiving therapist-directed RT; this is unlikely because
hospital stay was not affected by protocol type, regardless
of disease severity.
Previous studies have shown that RT delivered by protocol is beneficial in several ways, including cost savings,
hastened mechanical ventilation weaning times, reduced
time spent in intensive care, and reduced number of subjects returning to the ICU because of complications.4,7,8 In
addition, Tramacere et al11 showed that RT delivered by
protocol results in more timely implementation of therapy.
To our knowledge, no previous studies have addressed the
effect of therapist-directed protocols on 30-d readmission
rate and hospital stay for COPD subjects.
Limitations
Retrospective studies do not allow for random assignment to treatment groups or active control of confounding variables; causal relationships cannot be definitively
established. It is possible that a comparison of 30-d readmission frequencies between physician-directed and
therapist-directed groups would yield different results if
the groups were more comparable in size.
In this sample of 244 subjects, neither the type of protocol (therapist-directed or physician-directed) used nor
the age of the subject had a significant effect on hospital
stay. Because treatment is generally timelier when RT
protocols are used, one could reasonably speculate that RT
protocols would be associated with a shorter hospital stay;
In our study, protocol RT did not confer a disadvantage
to subjects in terms of hospital stay compared with nonprotocol RT. Overall, the results show that treatment ef-
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153
Conclusions
RESPIRATORY THERAPIST- VS PHYSICIAN-DIRECTED CARE IN COPD SUBJECTS
ficacy was not sacrificed when RT was directed by respiratory therapists rather than by physicians, regardless of
disease severity. In addition, the results suggest that
therapist-directed protocols may have been of some benefit in reducing 30-d post-discharge readmissions.
ACKNOWLEDGMENTS
We thank Michael G Parker PhD PT (University of Mary, Bismarck,
North Dakota) for his assistance with statistical analysis.
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This article is approved for Continuing Respiratory Care Education
credit. For information and to obtain your CRCE
(free to AARC members) visit
www.rcjournal.com
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