2.2 Outcome and Data Collection
System-reported clinical and administrative data from HVHC’s Unified
Data Extract included information about which patients underwent
arthroplasty within the grant period. Encounter-level data encompassing
demographic information, administrative claims, and health status
measures from HVHC system sites between 2012-2015 were integrated with
the Unified Data Extract and analyzed. Decision aid exposure was
documented in administrative data at the patient level. Patients’
post-decision aid treatment choices were assessed via patient survey
data. Patients were asked the following question after viewing decision
aids: “At this time, what treatment are you leaning toward for your
[hip/knee] pain?” Response categories included [hip/knee]
surgery, non-surgical treatment, or not sure.
The patient surveys also captured most patient-level independent
variables included in the final analyses – patient sex, age, marital
status, race, health insurance, education, HOOS/KOOS pain score, and
decision-making stage. The Hip Disability and Osteoarthritis Outcome
Score (HOOS) and Knee Disability and Osteoarthritis Outcome Score (KOOS)
10-item and 9-item (respectively) pain subscales were each normalized on
a 0-100 scale for analysis (in which 0 indicates no pain and 100
indicates extreme hip or knee pain) and subsequently divided into even
terciles corresponding to “low,” “medium,” and “high” categories.
The HOOS and KOOS instruments have both been shown to reliably and
validly assess short- and long-term pain experienced by patients with
osteoarthritis.25,26 To assess decision-making stage,
patients were asked the following question after viewing decision aids:
“How far along are you with this decision?” Possible responses
included the following: [1] “Not yet thought about all of the
options,” [2] “Considering the different options,” [3] Close
to choosing an option,” and [4] “Already chose an option.” Due to
small cell sizes for response [1], responses [1] and [2]
were collapsed into a single category to facilitate analysis (renamed
“Still considering options” to distinguish it from the original
response categories).
The HVHC Unified Data Extract included ICD-9 procedure codes 81.54 (knee
arthroplasty) or 81.51 (hip arthroplasty) which were used to classify
patients as having received surgery within 6 months of their orthopedic
consultations. The Charlson Comorbidity Index (CCI) was also constructed
using data drawn from the Unified Data Extract to determine the
comorbidity burden of the hip and knee osteoarthritis patients included
in the final analytic sample. The CCI is a continuous measure that
weights the sum of 17 common comorbid conditions.27