Table 3 Univariate and multivariate logistic regression analysis of the significant predictors of postoperative aggravation of renal function (A) both the group that was followed up for all 36 months and the group that showed normal results and was followed up only until the 1^st or 2^nd year, (B) the group followed up for the full 36 months

(A)

Univariate

Multivariate

p-value

OR

95% CI

p-value

OR

95% CI

Age > 60

0.522

1.022

0.955 - 1.094

Body mass index

0.627

0.931

0.699 - 1.241

Diabetes mellitus

0.808

1.393

0.096 - 20.226

Hypertension

0.869

1.151

0.215 - 6.165

Mini-PCNL (vs RIRS)

0.127

4.578

0.648 - 32.363

Laterality (Left)

0.310

2.287

0.463–11.295

Previous SWL

0.391

0.463

0.080 - 2.692

Previous stone procedure

0.216

3.154

0.511 - 19.485

Preoperative creatinine

0.133

8.037

0.530 - 121.881

0.064†

5.451

0.906–32.791

Preoperative hydronephrosis

0.001*

34.710

4.533–265.772

0.001*

12.433

2.919–52.963

Operation time > 90 min

0.297

2.784

0.406–19.085

Number of stones > 3

0.373

2.154

0.399–11.630

Total stone volume > 1,000 mm³

0.678

0.653

0.088–4.871

S-ReSC > 3

0.072†

5.515

0.856–35.525

0.039*

6.139

1.100–34.267

Hounsfield unit > 1,000

0.650

0.694

0.144–3.352

 (B)

Univariate

Multivariate

p-value

OR

95% CI

p-value

OR

95% CI

Age > 60

0.929

1.087

0.176 - 6.727

Body mass index

0.232

0.837

0.625 - 1.121

Diabetes mellitus

0.249

6.022

0.284 - 127.793

0.069†

10.902

0.831–143.096

Hypertension

0.961

1.053

0.133 - 8.306

RIRS (vs mini-PCNL)

0.179

0.157

0.011 - 2.340

0.045^*

0.113

0.013–0.950

Laterality (Left)

0.917

0.910

0.156 - 5.312

Previous SWL

0.972

0.965

0.133 - 7.001

Previous stone procedure

0.353

0.313

0.027 - 3.633

Preoperative creatinine

0.022^*

95.955

1.912 - 4816.390

0.003^*

154.202

5.733–4147.921

Preoperative hydronephrosis

0.126

10.853

0.511–230.546

0.032^*

13.428

1.256–143.509

Operation time > 90 min

0.597

2.153

0.125–37.081

Number of stones > 3

0.488

0.452

0.048–4.263

Total stone volume > 1,000 mm³

0.193

0.116

0.005–2.972

0.056†

0.104

0.010–1.060

S-ReSC > 3

0.047^*

26.677

1.042–682.765

0.009^*

25.234

2.203–289.027

Hounsfield unit > 1,000

0.519

1.942

0.259–14.578

Maximal diameter of stone

0.640

1.023

0.930–1.125

OR odds ratio, CI confidence interval, S-ReSC Seoul National University Renal Stone Complexity, RIRS retrograde intrarenal surgery, mini-PCNL miniaturized percutaneous nephrolithotomy, SWL shock wave lithotripsy