Table 2 Regression results

A. ICD-9-CM era

 Average year-over-year change, 2000–2014

0.03% ↓

0.82% ↑

2.20% ↑

3.02% ↓

2.85% ↑

0.22% ↑

0.20 ↑

(p = 0.977)

(p = 0.046)

(p = 0.001)

(p = 0.005)

(p = 0.000)

(p = 0.742)

(p = 0.673)

 R-squared

0.0001

0.1854

0.4006

0.4934

0.4406

0.0085

0.0114

 Observations

15

15

15

15

15

15

15

B. ICD-10-CM era

 Average year-over-year change, 2016–2020

0.27% ↓

11.89% ↑

1.05% ↑

1.60% ↓

7.72% ↓

4.69% ↑

7.68 ↑

(p = 0.961)

(p = 0.071)

(p = 0.452)

(p = 0.617)

(p = 0.161)

(p = 0.358)

(p = 0.285)

 R-Squared

0.0011

0.7288

0.1372

0.0826

0.3724

0.3027

0.3916

 Observations

5

5

5

5

5

5

5

 Average year-over-year change, 2016–2019

8.45% ↓

4.80% ↑

0.19% ↑

6.23% ↓

5.72% ↓

2.34% ↓

1.85 ↓

(p = 0.007)

(p = 0.051)

(p = 0.945)

(p = 0.093)

(p = 0.604)

(p = 0.099)

(p = 0.096)

 R-Squared

0.9661

0.8321

0.0030

0.7313

0.1453

0.6881

0.6846

 Observations

4

4

4

4

4

4

4

C. ICD-9-CM & ICD-10-CM eras

 Average year-over-year change, 2000–2014 & 2016–2020

0.64% ↓

4.55% ↑

2.14% ↑

4.04% ↓

0.40% ↑

1.08% ↑

1.32 ↑

(p = 0.274)

(p = 0.000)

(p = 0.000)

(p = 0.000)

(p = 0.614)

(p = 0.037)

(p = 0.039)

 R-squared

0.0787

0.6617

0.6175

0.7775

0.0169

0.2525

0.3186

 Observations

20

20

20

20

20

20

20

 Average year-over-year change, 2000–2014 & 2016–2019

0.88% ↓

3.76% ↑

2.15% ↑

4.18% ↓

0.93% ↑

0.66% ↑

0.70 ↑

(p = 0.155)

(p = 0.000)

(p = 0.000)

(p = 0.000)

(p = 0.261)

(p = 0.082)

(p = 0.016)

 R-Squared

0.1277

0.6325

0.5810

0.7662

0.0868

0.1312

0.2142

 Observations

19

19

19

19

19

19

19