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Calculate the case burden rate of a sports-related health problem (e.g. disease, injury) in a cohort.

Usage

calc_burden(
  injd,
  by = NULL,
  overall = TRUE,
  method = c("poisson", "negbin", "zinfpois", "zinfnb"),
  se = TRUE,
  conf_level = 0.95,
  scale = TRUE,
  quiet = FALSE
)

Arguments

injd

injd S3 object (see prepare_all()).

by

Character specifying the name of the column according to which compute summary statistics. It should refer to a (categorical) variable that describes a grouping factor (e.g. "type of case or injury", "injury location", "sports club"). Optional, defaults to NULL.

overall

Logical, whether to calculate overall (for all the cohort) or athlete-wise summary statistic (i.e. number of cases per cohort of per athlete). Defaults to TRUE.

method

Method to estimate the incidence (burden) rate. One of "poisson", "negbin", "zinfpois" or "zinfnb"; that stand for Poisson method, negative binomial method, zero-inflated Poisson and zero-inflated negative binomial.

se

Logical, whether to calculate the confidence interval related to the rate.

conf_level

Confidence level (defaults to 0.95).

scale

Logical, whether to transform the incidence and burden rates output according to the unit of exposure (defaults to TRUE).

quiet

Logical, whether or not to silence the warning messages (defaults to FALSE).

Value

The case burden rate. Either a numeric value (if overall TRUE) or a data frame indicating the case burden rate per athlete.

References

Bahr R., Clarsen B., & Ekstrand J. (2018). Why we should focus on the burden of injuries and illnesses, not just their incidence. British Journal of Sports Medicine, 52(16), 1018–1021. https://doi.org/10.1136/bjsports-2017-098160

Waldén M., Mountjoy M., McCall A., Serner A., Massey A., Tol J. L., ... & Andersen T. E. (2023). Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020. British journal of sports medicine.

Examples

calc_burden(injd)
#> Warning: 
#>   Exposure time unit is matches_minutes
#>   Case incidence and case burden are calculated per 100 athlete-matches of exposure (i.e. 90 minutes times 100)
#> 
#> # A tibble: 1 × 6
#>   totalexpo ndayslost burden burden_sd burden_lower burden_upper
#>       <dbl>     <dbl>  <dbl>     <dbl>        <dbl>        <dbl>
#> 1     74690      2049   247.      5.45         236.         258.
calc_burden(injd, overall = FALSE)
#> Warning: 
#>   Exposure time unit is matches_minutes
#>   Case incidence and case burden are calculated per 100 athlete-matches of exposure (i.e. 90 minutes times 100)
#> 
#> # A tibble: 28 × 7
#>    person_id      totalexpo ndayslost burden burden_sd burden_lower burden_upper
#>    <fct>              <dbl>     <dbl>  <dbl>     <dbl>        <dbl>        <dbl>
#>  1 adam-lallana         700       302 3883.     223.         3445.        4321. 
#>  2 alberto-moreno      1264        50  356.      50.3         257.         455. 
#>  3 alex-oxlade-c…      1483       316 1918.     108.         1706.        2129. 
#>  4 alisson             3420         0    0        0             0            0  
#>  5 andrew-robert…      5162        22   38.4      8.18         22.3         54.4
#>  6 daniel-sturri…       927       122 1184.     107.          974.        1395. 
#>  7 danny-ings           265         0    0        0             0            0  
#>  8 dejan-lovren        3109       160  463.      36.6         391.         535. 
#>  9 divock-origi         366         5  123.      55.0          15.2        231. 
#> 10 dominic-solan…       581         0    0        0             0            0  
#> # ℹ 18 more rows
calc_burden(injd, by = "injury_type")
#> Warning: 
#>   Exposure time unit is matches_minutes
#>   Case incidence and case burden are calculated per 100 athlete-matches of exposure (i.e. 90 minutes times 100)
#> 
#> # A tibble: 5 × 7
#>   injury_type totalexpo ndayslost burden burden_sd burden_lower burden_upper
#>   <chr>           <dbl>     <dbl>  <dbl>     <dbl>        <dbl>        <dbl>
#> 1 Bone            74690       173   20.8      1.58         17.7         24.0
#> 2 Concussion      74690       213   25.7      1.76         22.2         29.1
#> 3 Ligament        74690       596   71.8      2.94         66.1         77.6
#> 4 Muscle          74690       735   88.6      3.27         82.2         95.0
#> 5 Unknown         74690       332   40.0      2.20         35.7         44.3