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Operationalizing These Data to Inform
Medical Treatment
James Rae Scientific Day May 9, 2014
Nancy Hansen Merbitz, PhD
Clinical Assistant Professor
Division of Rehabilitation Psychology and Neuropsychology
U-M Department of Physical Medicine and Rehabilitation
“Behavior is the Central Outcome in Health Care”
- Robert M Kaplan, Chief Science Officer,
Agency for Healthcare Research and Quality
In his 1994 article on outcomes in health research, Kaplan cited the comic strip Ziggy.
The Guru responds to Ziggy:
“The meaning of life, my boy,
is doin' stuff!! …
As opposed to death, which
is NOT doin' stuff!”
Ziggy says:
‘”It's a more elementary theory than I had expected,
but one you can't argue with.”
In rehabilitation, we have always understood that our outcomes are behaviors (“doin’ stuff”).
According to the context and the question, behavior may be a(n):
Independent Variable “If the patient can practice frequently, his muscle strength will
improve.”
Moderator or Mediator Variable “The relationship between stress and illness is mediated by
health-related behaviors.”
Dependent Variable Resulting from illness: “The patient with hepatic
encephalopathy became delirious.”
An outcome of treatment: “After ammonia
levels were reduced, the delirium resolved.”
The rehabilitation unit is a goldmine of behavioral data.
Behavioral data can inform us about:
the patient’s progress in therapies,
the sensitivity of the human organism to changes in lab values or medication regimens that are not usually considered as having a clinical impact.
and the pt’s response to medical intervention.
Behavioral data are contained in our medical charts
Most of it is in rough, narrative form – currently difficult to extract.
“Patient gave correct information about person, place, time and circumstances.”
“Patient completed 10 reps on the rickshaw.”
A rough (but important and quantifiable) measure of patient behavior during rehabilitation:
MINUTES OF THERAPY COMPLETED
PER DAY
(i.e. “participation”).
Participation as a Dependent Variable:
The behavioral variable, “participation” (in this case defined as minutes of therapy completed per day), can be tracked to yield information about:
the clinical effects of a medical problem, as indicated by worsening behavior, and/or
the response to a medical intervention, as indicated by improved behavior.
This can be viewed as an opportunity for the application of
“pragmatic science” to medical practice.
Pragmatic science, using locally available information in context,
tracking it over time
Toward “a new epistomology of evidence-based practice” - Don Berwick, 2005; 2009
Founded the Institute for Healthcare Improvement
Nationally/internationally renowned in bringing methods of QI to healthcare settings large and small; forming networks of learning collaboratives
Berwick gives an unapologetic depiction of quality improvement as a compelling science.
Berwick (2005) summarizes key elements of pragmatic science (Brock, Nolan, & Nolan, 1998; Langley et al., 1996):
Tracking effects over time, especially with graphs (rather than summarizing with statistics that do not retain the information
involved in sequences);
Using local knowledge in measurement (rather than relegating measurement to people least familiar with the
subject matter and work);
Integrating detailed process knowledge into the work of interpretation (inviting observers to comment on what they notice rather than “blinding”
them to protect them against what they know);
Using small samples and short experimental cycles to learn quickly (rather than overpowering studies and delaying new
theories with samples larger than needed at the time).
In this case example We can see an opportunity to use data tracking to
look for possible relationships,
with “minutes of therapy” serving as the dependent (behavioral) variable.
Minutes of therapy in this case seems to indicate both
the clinical manifestation of hyponatremia (in the context of multiple co-morbidities increasing vulnerability to fatigue and delirium),
And the response to successful medical intervention.
hyponatremia
Is described as the most common electrolyte abnormality encountered in clinical practice.
Thompson. Hyponatraemia: new associations and new
treatments. Eur J Endocrinol. 2010 Jun;162 Suppl 1:S1-3
Many causes, with a subset related to medications.
Mr. C’s behavioral data
seem to indicate that there was a clinical effect of hyponatremia
at levels often considered to be “asymptomatic”.
“Asymptomatic hyponatremia”
“Is asymptomatic hyponatremia really asymptomatic?” Renneboog, et al., Am J Med, 2006
“Mild chronic hyponatremia is associated with falls, unsteadiness, and attention deficits”
Decaux, Am J Med, 2006
“Mild chronic hyponatremia (SNa 128 ± 3 mmol/L) was associated with similar but worse results on tests of attention and balance compared to matched normal controls with blood alcohol levels
of 0.6 g/L .” Hoorn et al., Clinical Kidney Journal, 2009
There can be subtle effects at mild levels of derangement.
Symptoms can be more notable when drop in sodium is rapid versus slow.
In the rehab setting, we may get a clearer picture of subtle symptoms because of close observation in a demanding environment.
Neurological signs
At different severity levels, there may be:
Mild (125 and 130 mmol/l)
○ anorexia, headache, nausea, vomiting, lethargy.
Moderate (115 and 125 mmol/l)
○ personality change, muscle cramps and weakness, confusion, ataxia.
Severe (<115 mmol/l )
○ drowsiness; seizures, coma
Our patient, Mr. C had a history of:
coronary artery disease (2 vessel CABG 1990)
chronic systolic heart failure
“pulseless episode” w/ approx 4 min unconscious, 2004
type 2 diabetes mellitus,
stage III chronic kidney disease,
hypertension,
hyperlipidemia,
GERD, possible esophageal dysmotility,
depression, anxiety, and
recent posterior spinal fusion for cervical stenosis.
Chronology of pt’s hyponatremia:
He was admitted to Acute Rehab from the Neurosurg unit, where his sodium level had fluctuated. It was decreasing just prior to his admit to rehab.
He also had pulmonary edema & SOB; benzo’s were decreased, and then citalopram was doubled as he became more anxious.
He was admitted to acute rehab, and sodium continued downward rapidly.
Various measures were taken to correct it, and ultimately these were successful.
115
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3-Feb 10-Feb 17-Feb 24-Feb 3-Mar 10-Mar 17-Mar 24-Mar 31-Mar 7-Apr 14-Apr
Sod
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Successsive Days (Sundays Labelled)
Trend in Sodium Lab Values
Na
Chronology of pt’s participation:
After his first weekend, he “ramped up” to full days of therapy (180+ minutes) on Monday and Tuesday, February 25 - 26.
But notice that as his sodium went down, and prior to onset of frank delirium:
He appeared more lethargic, depressed and anxious.
His minutes of therapy dropped to zero.
He was described as: “unmotivated”; “refusing therapy”.
Discharge to SAR was planned.
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Therapy Time
total time
“Tell them I’m not usually like this.”
“I want to get up. I want to get better.”
“I’m not lazy. I don’t feel right.”
“I just can’t do it.”
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Calendar Days
Therapy Time and Sodium Lab Values Trending Together
Na total time
On 3/6/13 confusion/altered mental status was first documented by nursing.
General Medicine consult: “SIADH is probable; etiology unknown but possible etiologies include citalopram”
On 3/7/13 “clinical picture is consistent with SIADH”.
He was placed on 500 cc fluid restriction; recommendation was to “discontinue diazepam” and “hold citalopram and tamsulosin”.
Held: diazepam (3/7).
DC’d: citalopram & tamsulosin (3/12).
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3-Feb 10-Feb 17-Feb 24-Feb 3-Mar 10-Mar 17-Mar 24-Mar 31-Mar 7-Apr 14-Apr
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Successive Days (Sundays labelled)
Medications and Sodium Lab Values
Na Citalopram 20-40 mg Tamsulosin .4 mg Diazepam 15-2 mg Lorazepam .5-1 mg
Fluids restricted500cc
Fluids restricted1000cc and
UTI dx'd
Fluid restrictionlifted
Sodium levels rose steadily, and held WNL. Mood, alertness, and minutes of therapy rose as well. Even swallowing improved to “within functional limits”.
Mood, alertness, minutes of therapy and swallowing maintained even as fluid restriction was lifted and furosemide was re-started.
Conclusion was: “SIADH 2/2 medications; likely citalopram, tamsulosin”
He discharged to home with his daughter. At follow-up appointment 1 month later, reported he was doing household ambulation w/ walker.
