Coding and Statistics

Coding and Statistics

• Transgender Breast Augmentation
• Covered by Medicaid and Medicare, military, most private payers
• Breast reconstruction has a separate code for women with breast cancer
• Code
• “bilateral augmentation mammaplasty with prosthetic implant”
• Considered to be reconstructive in this population
• Breast Reconstruction Coding
• CPT code for tissue expander to implant 
• “replacement of tissue expander with permanent prosthesis”
• This includes excision of mastectomy scar
• Coding for revision of reconstructed breast is only after reconstruction 
• This does not refer to stage II with implant placement
• Fat grafting is a separate code
• 20926 (Tissue grafts or other) 
• Used for fat grafting for pole deformities
• No other codes necessary for fat grafting (like fat harvest etc)
• Breast reconstruction with free flap
• Code includes rib resection, microscope use, complex closure, flap harvest, shaping of breast
• May code for use of indocyanine green separately (not interpretation and report)
• May code for any hernia repair that is not created by flap defect
• Rhinoplasty coding
• Septoplasty
• Use this code for septoplasty only including submucous resection and harvest of cartilage
• For spreader graft placement for internal valve collapse 
• Use vestibular stenosis code if performing septoplasty in conjunction 
• This already includes septal cartilage harvest
• Rhinoplasty code involves lower alar cartilages, bony pyramid
• Facial fractures coding
• Zygomaticomaxillary (ZMC) complex fractures are classified as ORIF of malar fracture or “complex” malar fracture
• Complex is necessitated if there are multiple incisions or if the fracture crosses the infraorbital foramen
• Orbital floor fractures if fixed are coded separately even though they are common in ZMC fractures
• Code includes repair with periorbital approach with alloplastic implant
• General Coding
• Random pattern flaps (IE rhomboid flaps) are coded as adjacent tissue transfer
• If this is coded, the excision of lesion is not separately reportable 
• Separate reporting would be considered unbundling
• Size of closure or tissue rearrangement includes total area
• Size of defect + size of flap elevated 
• The size of reconstruction of the flap defect not included in coding as it is already included by the secondary defect measurement
• However, reconstruction techniques of the donor site is included in coding
• Flaps based on an axial pattern named vessel (IE Karapandzic flap based on facial artery) is coded as a musculocutaneous flap or fasciocutaneous flap depending on components
• TMR is considered nerve transfer and is coded as such
• Medicare and Medicaid Reimbursements
• Mostly followed by third party payers
• Global surgical package is a single payment for all care associated with a surgical procedure 
• Some things are not separately billable
• Services not included in the global package
• Unrelated visits, unrelated surgeries, and initial evaluation
• Global period (90 days for major surgery)
• Pre-operative visits after surgery decision made
• All post-surgical visits and pain care
• Supplies and procedures
• Suture removal
• Does NOT include complications that require return to operating room
• Statistical Analysis
• Common measures of central tendency
• Mean—statistical average, prone to change when data is highly skewed
• Median—the exact middle value, preferred with highly skewed data
• Mode—most frequently occurring score in a set of scores
• Range—distance between minimum and maximum value
• Standard deviation—how spread out the values are in a data set
• Categorical values—cannot be quantified; usually assessed by nonparametric statistics
• Continuous variable—a variable that gives a score for each subject (blood pressure, cholesterol); use parametric to assess
• Parametric tests assume that the data are normally distributed 
• T test, ANOVA, Chi Square
• Nonparametric tests are typically more stringent because they are based on the assumption of nonnormal distribution
• Ordinal or nominal, Mann-Whitney U test, fischer exact test, wilcoxon matched pairs test
• P-Value—probability that the outcome would have occurred by chance (set at 0.05)
• Confidence interval—range of values around a sample mean within which the researcher can be certain contains true mean of population
• Sensitivity—the probability that a patient with a disease will have a positive test result
• Specificity—the probability that a patient without a disease will have a negative test result
• Positive predictive value—the probability that a patient with a positive test result has the disease (specificity) 
• The negative predictive value—the probability that a patient with a negative test result does not have the disease (sensitivity)
• Types of Error
• Type I error—probability of falsely rejecting the null hypothesis (when a researcher concludes that there is a difference between two conditions when there is no difference
• Type II error—probability of failing to reject null hypothesis when it is true, and the researcher concludes there is no difference between two conditions when there is a real difference
• Null hypothesis—that there is no real difference between the two groups
• Power—the term that refers to the statistical likelihood that a researcher will find a significant effect that exists based on the sample size and number of variables