Data for The puzzling popularity of back surgery in certain regions

Link to article:

The puzzling popularity of back surgery in certain regions
Frakt A, Skinner J. The puzzling popularity of back surgery in certain regions. NY Times. 2017 Feb 13. https://www.nytimes.com/2017/02/13/upshot/medical-mystery-why-is-back-surgery-so-popular-in-casper-wyo.html

Data Download(1992-2014)

Methods

Research Methods for Back Surgery Series

Methods developed by John E. Wennberg and the Dartmouth Atlas working group (1992-2000) and Brook Martin (2001-14).

Implemented by Sandra Sharp

Notes compiled by Jonathan Skinner

Maps created by Kristen Bronner

A. All rates are rates are based on the Medicare fee-for-service population age 65-99 enrolled in Parts A and B. Exclusions include enrollees who are in Medicare Managed Care for any month during the calendar year, and those eligible because of End-Stage Renal Disease.

B. Regional measures are adjusted for differences in age (5-year intervals), sex, and race (black or non-black), by Hospital Referral Region (HRR) as described in the Dartmouth Atlas Appendix

Note that the Atlas measures are adjusted to the age-sex-race composition of the elderly Medicare fee-for-service population for a given calendar year. However, there may also be changes over time in (e.g.) average age that will not be adjusted for in these estimates. However, generally back surgery declines with age, so an older age composition is not necessarily predictive of higher surgical rates.

C. There are two distinct series of data. The first set of annual rates, from 1992-2000, are based on inpatient back surgery only and come directly from the Dartmouth Atlas database. Table 1 below presents the ICD-9 procedure and diagnosis codes used to define back surgery admissions. The second set, from 2001-2014, includes both inpatient and outpatient rates, and were developed as part of an National Institute on Aging project to create databases focused on diffusion; the entire database can be accessed here: atlasdata.dartmouth.edu

The “seam” is therefore between 2000 and 2001. However, in comparing the new (inpatient plus outpatient) with the old (inpatient only) 2001 data, the new data is on average just 3% higher, and the correlation coefficient between the new 2001 data and the old 2001 data, by HRR, is 0.99.

D. For the 2001-14 data, “Surgery” includes the procedure variables from Brook Martin’s algorithm that defines discectomy (SPTXDECO), fusion (SPTXFUS), artificial disc (SPTXADR), or spinal distraction devices (SPTXSPACER); the defining ICD-9 and CPT codes are presented in Table 2 below (ICD-9 for MedPAR, CPT for part B and outpatient data). The incident record of spine surgery for each beneficiary was identified on an annual basis using MedPAR and outpatient claims, which was then linked on BENE_ID with Part B data to provide additional corroborating information. (We did not retain the Part-B-only sample since for early years we have only a 40% sample.)

Table1: Codes Used to Define Back Surgery for 1992-2000 data (Dartmouth Atlas)

Inpatient Surgical Procedures

Event

ICD-9 Procedure Code(s)

&/or Diagnosis Code(s)

Orthopedic Surgery

Back surgery

03.0, 03.02, 03.09, 03.6, 80.50-80.54, 80.59, 81.00-81.09, 81.31-81.39, 81.61-81.64, 84.60-84.69

Excluding DX codes 140-239.9, 324.1, 630-676, 720.0-720.9, 730-730.99, 733.1, 733.10, 733.13, 733.8, 733.81-733.82, 733.95, 805-806.9, 839-839.59, E800-E849.9: SX codes 03.2-03.29

03.93, 03.94, 78.50, 78.59, 78.60, 78.69, 78.90, 78.99, 84.51, 84.52, 84.58, 84.59, 84.80-84.85

With exclusions above and only with DX codes = 353.9, 355.0, 355.9, 721.0-721.4, 721.42, 721.7-721.9, 721.90, 721.91, 722.0, 722.10, 722.11, 722.2, 722.4, 722.5, 722.51, 722.52, 722.6, 722.70-722.73, 722.80, 722.81, 722.83, 722.90-722.93, 723.0, 723.1, 723.8, 724.00-724.02, 724.09, 724.2-724.6, 724.70, 724.71, 724.79, 724.8, 724.9, 737.0, 737.1, 737.10, 737.19, 737.20, 737.3, 737.30, 737.32, 737.34, 737.39, 737.43, 737.8, 737.9, 738.4, 756.11, 756.12, 846.0, 846.1-846.3, 846.8, 846.9, 847.0, 847.2, 847.9

Table2: Codes Used to Define Back Surgery for 2001-2014 data (B. Martin)

Create indicator variables for procedures by examining all listed ICD-9 procedure codes (MedPAR), and CPT codes (Part B & outpatient data) at time of surgery.

Surgical procedure

Variable

ICD-9 Procedure codes

Decompression:


(Discectomy / Laminectomy / Laminotomy)

SPTXDECO

CPT codes


63001 63003 63005 63011 63012 63030 63035 63042 63044 63017 63047 63048 63015 63016 63020 63040 63043 63045 63046 63050 63051 63172 63173 63182 63185 63191 63194 63195 63196 63197 63198 63199 63170 63180 63200 63250 63251 63252 63265 63266 63267 63268 63270 63271 63272 63273 63295 63170 63190 63275 63278 63280 63281 63282 63283 63285 63287 63290 63010 63075 63076 63077 63078 63055 63056 63057 63064 63066


ICD-9 Procedure codes


03.0 03.02 03.09 80.50 80.51 80.53 80.54 80.59

Fusion

SPTXFUS

CPT codes


20930 20931 20936 20937 20938 22558 22585 22612 22614 22630 22830 22840 22841 22842 22843 22844 22845 22846 22847 22849 22851 22625 22650 22632 22532 22533 22534 22548 22554 22556 22590 22595 22600 22610 22800 22802 22804 22808 22810 22812 22848 22850 22852 22855 22633


ICD-9 Procedure codes


78.50 78.59 81.0 81.00 81.01 81.02 81.03 81.04 81.05 81.06 81.07 81.08 81.09 81.31 81.32 81.33 81.34 81.35 81.36 81.37 81.38 81.39 81.61 81.62 81.63 81.64 84.51

Artificial disc

SPTXADR

CPT codes


22856 22857 0092T 0163T 22864 22865 0095T 0164T 22861 22862 0098T 0165T


ICD-9 Procedure codes


84.6 84.60 84.61 84.62 84.63 84.64 84.65 84.66 84.67 84.68 84.69

Spinal Spacers or dynamic stabilizing devices

SPTXSPACER

CPT codes


0171T 0172T


ICD-9 Procedure codes


84.58 84.80 84.81 84.82 84.83 84.84 84.85

Exclude patients with the following medical conditions at time of surgery:

Condition

Variable

ICD-9 Diagnosis codes

Cancer

EX1

140-208 230-239

Trauma

EX2

800-804.99 839 850-854 860-869 905-909 926.11 926.12 929 952 958-959 E800-E849.9 E916-E928

Drug abuse

EX3

304.0 304.1* 304.2* 304.4* 305.4* 305.5* 305.6* 305.7*

Neurological impairment

EX4

344.60 729.2 344.6 952.4

HIV or immune deficiency

EX5

042-044 279.3 V08

Intraspinal abscess

EX6

324.9 324.1

Osteomylitis

EX7

730.0 730.00 730.08 730.09 730.1 730.15 730.18 730.19 730.2 730.21 730.25 730.28 730.29 730.3 730.35 730.38 730.39 730.7 730.75 730.78 730.79 730.8 730.85 730.88 730.89 730.90 730.95 730.98 730.99