Skip to main content

Table 6 Reason for Algorithm Misclassification

From: Validation of an electronic coding algorithm to identify the primary indication of orthopedic surgeries from administrative data

Diagnosis Misclassification Reasons
Lumbar Herniated Disc (n = 29) False Positive (n = 13) Spinal Stenosis Case (n = 8)
Severe Incontinence Diagnosis (n = 1)
Cervical or Thoracic Spine Case (n = 1)
Flatback Syndrome Case (n = 1)
Spondylolisthesis Case (n = 1)
Revision Discectomy Case (n = 1)
False Negative (n = 16) Incorrectly Classified as Spinal Stenosis (n = 9)
Procedure Billing Codes not included in Data (n = 4)
Incorrectly Marked as Non-Primary Indication because of urinary incontinence diagnosis (n = 2)
Incorrectly Marked as Non-Primary Indication because of cauda equina diagnosis (n = 1)
Lumbar Spinal Stenosis (n = 46) False Positive (n = 16) Herniated Disc Case (n = 9)
Cervical or Thoracic Spine Case (n = 4)
Infection Present (n = 1)
Flatback Syndrome Case (n = 1)
Epidural Abscess Case (n = 1)
False Negative (n = 30) Procedure Billing Codes not included in Data (n = 11)
Incorrectly Classified as Herniated Disc (n = 8)
CPT code (63046, 63267) not included in algorithm (n = 6)
Incorrectly Marked as Non-Primary Indication because of collapsed vertebra diagnosis (n = 2)
Incorrectly Marked as Non-Primary Indication because of fecal incontinence diagnosis (n = 1)
Incorrectly Marked as Non-Primary Indication because of fracture diagnosis (n = 1)
Incorrectly marked as Non-Primary Indication because of bladder dysfunction diagnosis (n = 1)
Knee Osteoarthritis (n = 11) False Positive (n = 2) Procedure was actually to revise previous knee replacement (n = 1)
Rheumatoid Arthritis Case (n = 1)
False Negative (n = 9) Procedure Billing Codes not included in Data (n = 6)
CPT code (27486, 27487) not included in algorithm (n = 2)
Incorrectly Marked as Non-Primary Indication because of osteonecrosis diagnosis (n = 1)
Hip Osteoarthritis (n = 23) False Positive (n = 2) Osteonecrosis Diagnosis (n = 1)
Developmental Hip Dysplasia Case (n = 1)
False Negative (n = 21) Incorrectly Marked as Non-Primary Indication because of osteonecrosis diagnosis (n = 12)
Procedure Billing Codes not included in Data (n = 6)
CPT code (27134) not included in algorithm (n = 1)
Incorrectly Marked as Non-Primary Indication because of fracture diagnosis (n = 1)
Incorrectly Marked as Non-Primary Indication because of neoplasm diagnosis (n = 1)
\