Title Page

Contents

Abstract 8

Chapter 1. INTRODUCTION 10

Chapter 2. Methods 13

1. Study design 13

2. Restrictive calcium-replacement protocol 14

3. Data extraction 15

4. Outcome measures 16

5. Subgroup analysis 16

6. Statistical analysis 17

Chapter 3. Results 19

1. Patient baseline characteristics 19

2. Primary and secondary outcomes from hypocalcemia patients vs. non-hypocalcemia patients 22

3. Calcium replacement in the liberal group vs. restrictive group 24

4. Primary and secondary outcomes from liberal vs. restrictive groups 28

5. Subgroup interaction analysis 33

6. Variables associated with 28-day mortality 34

Chapter 4. Discussion 37

Chapter 5. Conclusions 42

References 43

Appendices 50

〈Appendix 1〉 Baseline characteristics for hypocalcemia patients. 50

〈Appendix 2〉 Absolute standardized mean difference before vs. after matching. 52

논문요약 53

Table 1. Baseline characteristics between hypocalcemia and non-hypocalcemia patients. 20

Table 2. Primary and secondary outcomes. 22

Table 3. Baseline differences between the liberal and restrictive groups. 25

Table 4. Primary and secondary outcomes (liberal group vs. restrictive group). 28

Table 5. Simple Cox proportional hazard analysis for clinical outcomes. 30

Table 6. Multiple Cox proportional hazard analysis for clinical outcomes. 32

Table 7. Subgroup analysis of the impact of reducing iCa administration on 28-day mortality. 33

Table 8. Univariable and multivariable logistic regression for 28-day mortality in the matched cohort. 34

Figure 1. Calcium-replacement protocol. 14

Figure 2. Study flowchart. 19

Figure 3. Relationship between iCa level and mortality according to the lowest iCa level. 23

Figure 4. 28-day mortality and in-hospital mortality according to the lowest iCa level (liberal group vs. restrictive group). 29

Figure 5. Kaplan-Meier analysis for 28-day mortality and shock reversal. 33