INVOKED Power

Aim 1

Determine the effect of higher versus standard dose influenza vaccine on AKI

• Sample: All hospitalization (n=900, \(n_S = 500\) and \(n_H = 400\))
• Exposure: High vs standard dose vaccine
• Outcomes: AKI during hospitalization (present or absent; estimated to occur in 15-20% of 900 hospitalizations)

X-axis is the relative Risk Reduction for High Dose Vaccine (\(1 - p_H / p_S\)). Each curve assumes the rate of AKI complication among hospitalization in the standard dose group (\(p_S\)). Cohort is the 900 hospitalization from main trial.

Aim 2

Determine the effect of higher versus standard dose influenza vaccine on death/cardiopulmonary hospitalizations in patients with CKD

• Sample: CKD patients (n=2,640)
• Exposure: High vs standard dose vaccine
• Outcomes: Death or Cardiopulmonary hospitalization (present or absent)

X-axis is the relative Risk Reduction for High Dose Vaccine (\(1 - p_H / p_S\)). Each curve assumes a proportion of CKD population in the whole cohort. Power is calculated by comparing two proportions.

Aim 3.1

Higher vs standard is associated with greater frequency of adequate immune response, as assessed by doubling of geometric mean antibody titers at 4 weeks

• Sample: CKD (n=900)
• Exposure: High vs standard dose vaccine
• Outcomes: Doubling of geometric mean titer (present or absent)

## [1] "n=900"

##    p.s    0.3   0.35   0.4
## 1 0.15 0.9998 1.0000 1.000
## 2 0.20 0.9350 0.9991 1.000
## 3 0.25 0.3896 0.9068 0.998

Row: response rate for standard dose group, 0.15, 0.2, 0.25;

Column: response rate for high dose group, 0.3, 0.35, 0.4.

Aim 3.2

• Sample: CKD (n=200)
• Exposure: CD4/CD8 ratio (continuous variable)
• Outcomes: Doubling of geometric mean titer (present or absent)

• Sample: CKD (n=200)
• Exposure: % CD28neg CD8+ T cells (continuous variable)
• Outcomes: Doubling of geometric mean titer (present or absent)

## [1] "n=200"

##    sd   0.06   0.08    0.1
## 1 0.2 0.8491 0.9788 0.9988
## 2 0.3 0.5140 0.7581 0.9139

Row: standard deviation, 0.2, 0.3;

Column: true difference in means, 0.06, 0.08, 0.1.