Table 3 Strength of the relationship and coefficient of determination between unit cost and program scale

Unit cost decrease associated with doubling of scale ¹

p-value of regression

Coefficient of determination (R²)

Unit cost decrease associated with doubling of scale ¹

p-value of regression

Coefficient of determination (R²)

Unit cost decrease associated with doubling of scale ¹

p-value of regression

Coefficient of determination (R²)

32.5%

< 0.001

0.83

41.8%

< 0.001

0.88

23.0%

0.038

0.42

15.3%

0.066

0.20

27.2%

0.021

0.28

41.0%

< 0.001

0.84

2.4%

0.033

0.33

31.2%

0.015

0.38

27.5%

0.045

0.29

STI

IEC

RR

52.4%

0.050

0.42

32.3%

0.038

0.70

46.3%

< 0.001

0.91

58.0%

0.385

0.26

34.5%/47.9% ²

0.004/0.022

0.45/0.96²