A data frame containing the age-dependent distribution of the D-score for children aged 0-5 years. The distribution is modelled after the LMS distribution (Cole & Green, 1992), and is equal for both boys and girls. The LMS values can be used to graph reference charts and to calculate age-conditonal Z-scores, also known as DAZ.

builtin_references

## Format

A data.frame with 265 rows and 17 variables:

 Name Label pop Population, either "dutch" or "gcdg" age Decimal age in years mu M-curve, median D-score, P50 sigma S-curve, spread expressed as coefficient of variation nu L-curve, the lambda coefficient of the LMS model for skewness P3 P3 percentile P10 P10 percentile P25 P25 percentile P50 P50 percentile P75 P75 percentile P90 P90 percentile P97 P97 percentile SDM2 -2SD centile SDM1 -1SD centile SD0 0SD centile, median SDP1 +1SD centile SDP2 +2SD centile

## Details

The "dutch" references were calculated from the SMOCC data, and cover age range 0-2.5 years (van Buuren, 2014). The "gcdg" references were calculated from the 15 cohorts of the GCDG-study, and cover age range 0-5 years (Weber, 2019).

## References

Cole TJ, Green PJ (1992). Smoothing reference centile curves: The LMS method and penalized likelihood. Statistics in Medicine, 11(10), 1305-1319.

Van Buuren S (2014). Growth charts of human development. Stat Methods Med Res, 23(4), 346-368. https://stefvanbuuren.name/publication/van-buuren-2014-gc/

Weber AM, Rubio-Codina M, Walker SP, van Buuren S, Eekhout I, Grantham-McGregor S, Caridad Araujo M, Chang SM, Fernald LCH, Hamadani JD, Hanlon A, Karam SM, Lozoff B, Ratsifandrihamanana L, Richter L, Black MM (2019). The D-score: a metric for interpreting the early development of infants and toddlers across global settings. BMJ Global Health, BMJ Global Health 4: e001724. https://gh.bmj.com/content/bmjgh/4/6/e001724.full.pdf

dscore()

## Examples

head(builtin_references)
#>     pop    age    mu  sigma     nu   P3   P10   P25   P50   P75   P90   P97
#> 1 dutch 0.0383  8.81 0.3126 1.3917 3.15  5.07  6.91  8.81 10.57 12.07 13.49
#> 2 dutch 0.0575 10.59 0.2801 1.4418 4.32  6.49  8.52 10.59 12.50 14.12 15.64
#> 3 dutch 0.0767 12.27 0.2526 1.4891 5.61  7.96 10.10 12.27 14.28 15.97 17.56
#> 4 dutch 0.0958 13.87 0.2291 1.5331 6.99  9.43 11.64 13.87 15.93 17.67 19.30
#> 5 dutch 0.1150 15.39 0.2089 1.5722 8.42 10.89 13.13 15.39 17.47 19.23 20.89
#> 6 dutch 0.1342 16.83 0.1916 1.6049 9.86 12.32 14.56 16.83 18.92 20.69 22.36
#>   SDM2  SDM1   SD0  SDP1  SDP2
#> 1 2.78  5.94  8.81 11.39 13.76
#> 2 3.88  7.46 10.59 13.38 15.94
#> 3 5.12  8.98 12.27 15.20 17.87
#> 4 6.47 10.48 13.87 16.87 19.61
#> 5 7.89 11.95 15.39 18.43 21.21
#> 6 9.33 13.39 16.83 19.88 22.68