Table 1 Growth screening rules with their definitions, interpretation of the used parameters and cut off (simulation) values (see method for details)

Delta rule*^{^}

For ages e ₁ to 2.5 years, refer if

e ₁

Age (in years) after which the rule is effective

0, 0.5, 1

(SDS₂ – SDS₁) <g ₁

g ₁

Change in SDS

-0.5,-1,-1.5,-2,-2.5,-3

Extended delta rule*

For ages e ₂ to 2.5 years, refer if

e ₂

Age (in years) after which the rule is effective

0, 0.5, 1

SDS₂<f ₁, AND

f ₁

SDS cut off level below which the SDS₂ must lie

-1,-1.3, -1.5,-2, -2.5

(SDS₂ – SDS₁) <g ₂

g ₂

Change in SDS

-0.5,-1,-1.5,-2,-2.5,-3

Slowed growth *

For ages e ₃ to 2.5 years, AND

e ₃

Age (in years) after which the rule is effective

0, 0.5, 1

X₂ – X₁ ≥ 3/12 refer if

Minimal three months interval between ages X₁ and X₂

SDS₂<f ₂, AND

f ₂

SDS cut off level below which the SDS₂ must lie

-1,-1.3, -1.5,-2, -2.5

(SDS₂- SDS₁)/(X₂-X₁) < g₃

g ₃

Change in SDS per year

-0.5,-1,-1.5,-2,-2.5

Conditional weight gain rule

For ages e ₄ to 2.5 years, refer if

e ₄

Age (in years) after which the rule is effective

0, 0.5, 1

weight SDS₂ <f ₃ AND

f ₃

SDS cut off level below which SDS₂ must lie

-1,-1.3, -1.5,-2, -2.5

weight SDSgain = (weight SDS₂ – r weight SDS₁)/(√1-r²) <g ₄

g ₄

Change in SDS

-0.5,-1,-1.5,-2,-2.5

Absolute SDS rule*

For ages 0 to e ₅ years, refer if

e ₅

Age (in years) at which the referral level changes

0, 0.5, 1

SDS <f ₄

f ₄

SDS cut off level before age e ₅

-1, -1.3, -1.5, -2, -2.5, -3, -3.5

For ages e ₅ to 2.5 years, refer if SDS <f ₅

f ₅

SDS cut off level after age e ₅

-1, -1.3, -1.5, -2, -2.5, -3

Parental height corrected rule

For ages e ₆ to 2.5 years, refer if

e ₆

Age (in years) after which the rule is effective

0, 0.5, 1

length SDS <f ₆, AND

f ₆

Length SDS must lie below this cut off level

-1, -1.3, -1.5, -2, -2.5

length SDS – TH SDS <g ₅

g ₅

Difference between length SDS and target height (TH) SDS

-1, -1.3, -1.5, -2, -2.5

Parental height deflection rule

For ages e ₇ to 2.5 years, refer if

e ₇

Age (in years) after which the rule is effective

0, 0.5, 1

(length SDS₂ – length SDS₁) <g ₆, AND | length SDS₂ – TH SDS | > | length SDS₁ – TH SDS |

g ₆

Change in length SDS Length SDS at age X₁ is closer to it's target height than length SDS at age X₂

-0.5,-1,-1.5,-2,-2.5,-3

Combined weight and length deflection rule

For ages e ₈ to 2.5 years, AND

e ₈

Age (in years) after which the rule is effective

0, 0.5, 1

(weight SDS₂ – weight SDS₁) <g ₇, AND

g ₇

Weight change in SDS

-0.25,-0.5,-1,-1.5,-2

(length SDS₂ – length SDS₁) <g ₈, AND Y₁ > X₁

g ₈

Length change in SDS Starting point length deflection (Y₁) after starting point weight deflection (X₁)

-0.25,-0.5,-1,-1.5,-2