Abstract
39. The cost and likelihood of requiring additional surgery within two years after index microdiscectomy
The spine journal, v 23(9), pp S20-S20
Sep 2023
Abstract
Patients undergoing microdiscectomy (CPT 63030, 63035) for the primary diagnosis of herniated nucleus pulposus causing radiculopathy (as opposed to patients undergoing laminectomy for spinal stenosis) may at times experience either reherniation or continued degeneration that would eventually require additional intervention involving a lumbar arthrodesis. The reported rate of reherniation ranges from 3 to 18%, those requiring repeat discectomy 10-19.5 %, and the eventual need for fusion is even less common at 2% (Finland population data).
Utilization of the unique dataset available to our institution of direct insurance claims data to define the likelihood and cost of additional surgery after initial microdisc.
Retrospective cohort design using insurance claims data.
Adults 18-90 (average age of 50) enrolled in a commercial Highmark BCBS insurance plan at the time of original microdisc surgery as defined by original surgery CPT code 63030/63035, excluding revision codes for immediate perioperative complications (infection, CSF leak repair) or ongoing conditions like cancer or severe deformity. The majority were male (n = 4,697, 58%) and 3,445 (42%) were female. Most patients had no major comorbidities 7,157 (88%).
Primary outcome was defined as the percent of patients had additional spine surgery in the form of any lumbar arthrodesis (ALIF, OLIF, XLIF, PLIF, TLIF, or PLF): CPT Codes: 22533, 22558, 22612, 22630, 22633. Secondary outcomes include the percent of patients having repeat microdiscectomy, the time interval to additional surgery, the cost of the additional lumbar surgical episode, perioperative workup and conservative measures.
Descriptive analyses assessed frequencies, means, medians, and ranges for demographic, costs, and health care utilization, stratified by whether the member had a microdiscectomy redo and whether the member had a fusion. To understand the time to additional procedures (ie, microdiscectomy redoes, fusions), Kaplan-Meier plots were used to show the time to these additional procedures, the risk over time, and predictors of the time to these additional procedures. Generalized linear modeling, specifically Cox proportional hazards regression, estimated the risk associated with the time to additional procedures. Costs were compared using generalized linear models with a gamma distribution and log link. These analyses used data from members that had the full 2 years of follow-up (n = 5,382), and therefore do not include members who did not have continuous enrollment for 2 years. The cost models compared PMPM costs by members who: 1) did and did not have a fusion procedure, and 2) did and did not have a microdiscectomy redo.
A total of 8,142 unique members were identified as having a primary index microdiscectomy with 77 (1%) of patients required at least one fusion at 180 days, 208 (3%) at 365 days, 306 (4%) at 1.5 years and 384 (6%) patients estimated to have transitioned to fusion 2-years postindex procedure. Age and sex significantly predicted the probability of needing a fusion procedure. Comorbidities did not significantly predict fusions, but in this sample sicker individuals were somewhat more likely to have a fusion. There was an 8% (615) likelihood of requiring additional (nonfusion) back surgery at 1 year and 14% (922) at 2 years. Of those 922 additional back surgeries, 567 were for microdiscectomy redos. Average per member per month (PMPM) costs preoperatively (baseline) were $1,509, the index procedure costs (inclusive of all costs accrued that encounter was $13,365. The PMPM during 6 months follow up was $1,173. Direct costs of additional postoperative care for ongoing discomfort included $24,135,529 for fusion surgeries (and other encounter-based care) and $17,371,682 for nonfusion surgeries, including microdiscectomy redos.
Commercially insured patients within our unique patient pool undergoing lumbar microdiscectomy had a 3% risk of fusion-based and 14% of nonfusion-based reintervention at 2 years. Patients going on to require additional intervention had an increased average per member per month cost preoperatively, and were more likely to have additional medical comorbidities.
This abstract does not discuss or include any applicable devices or drugs.
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Details
- Title
- 39. The cost and likelihood of requiring additional surgery within two years after index microdiscectomy
- Creators
- Dallas E. Kramer - Allegheny Health NetworkTyson Barrett - Nibley, USCharlotte Drury - Highmark Health, Pittsburgh, PA, USKeith Lejeune - Allegheny Health NetworkBoyle Cheng - Allegheny General HospitalEdward Prostko - Allegheny General HospitalLara Massie - Allegheny Health Network
- Publication Details
- The spine journal, v 23(9), pp S20-S20
- Publisher
- Elsevier
- Resource Type
- Abstract
- Language
- English
- Academic Unit
- Surgery
- Other Identifier
- 991021930322104721