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The IMPACT dataset comprises 15 studies of patients suffering from traumatic brain injury, including individual patient data from 11 randomized controlled trials and four observational studies.

Usage

data("impact")

Format

A data frame with 11022 observations on the following 11 variables.

name

Name of the study

type

Type of study, RCT: randomized controlled trial,OBS: observational cohort

age

Age of the patient

motor_score

Glasgow Coma Scale motor score

pupil

Pupillary reactivity

ct

Marshall Computerized Tomography classification

hypox

Hypoxia (0=no, 1=yes)

hypots

Hypotension (0=no, 1=yes)

tsah

Traumatic subarachnoid hemorrhage (0=no, 1=yes)

edh

Epidural hematoma (0=no, 1=yes)

mort

6-month mortality (0=alive, 1=dead)

Details

The included studies were part of the IMPACT project, where a total of 25 prognostic factors were considered for prediction of 6-month mortality. Missing values were imputed using the study as a fixed effect in the imputation model (Steyerberg et al, 2008).

Source

Steyerberg EW, Nieboer D, Debray TPA, Van Houwelingen JC. Assessment of heterogeneity in an individual participant data meta-analysis of prediction models: An overview and illustration. Stat Med. 2019;38(22):4290--309.

References

Murray GD, Butcher I, McHugh GS, et al. Multivariable prognostic analysis in traumatic brain injury: results from the IMPACT study. J Neurotrauma. 2007;24(2):329--337.

Steyerberg EW, Mushkudiani N, Perel P, et al. Predicting outcome after traumatic brain injury: development and international validation of prognostic scores based on admission characteristics. PLOS Med. 2008;5(8):e165.

Examples

data(impact)

by(impact, impact$name, summary)
#> impact$name: APOE
#>       name      type          age        motor_score  pupil        ct     
#>  APOE   :756   OBS:756   Min.   :14.00   1/2:  7     Both:638   I/II:377  
#>  CSTAT  :  0   RCT:  0   1st Qu.:25.00   3  :331     None: 79   III :151  
#>  EBIC   :  0             Median :37.00   4  : 18     One : 39   IV/V:228  
#>  HIT I  :  0             Mean   :41.14   5/6:400                          
#>  HIT II :  0             3rd Qu.:56.00                                    
#>  NABIS  :  0             Max.   :93.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah            edh         
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.000   Min.   :0.00000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.000   1st Qu.:0.00000  
#>  Median :0.0000   Median :0.0000   Median :0.000   Median :0.00000  
#>  Mean   :0.2712   Mean   :0.1071   Mean   :0.254   Mean   :0.06614  
#>  3rd Qu.:1.0000   3rd Qu.:0.0000   3rd Qu.:1.000   3rd Qu.:0.00000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.000   Max.   :1.00000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.1548  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: CSTAT
#>       name      type          age        motor_score  pupil        ct     
#>  CSTAT  :517   OBS:  0   Min.   :15.00   1/2:128     Both:368   I/II:212  
#>  APOE   :  0   RCT:517   1st Qu.:20.00   3  : 86     None: 63   III :105  
#>  EBIC   :  0             Median :28.00   4  :180     One : 86   IV/V:200  
#>  HIT I  :  0             Mean   :31.79   5/6:123                          
#>  HIT II :  0             3rd Qu.:41.00                                    
#>  NABIS  :  0             Max.   :68.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :0.0000   Median :0.0000  
#>  Mean   :0.1335   Mean   :0.1663   Mean   :0.4778   Mean   :0.1161  
#>  3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2224  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: EBIC
#>       name      type          age        motor_score  pupil        ct     
#>  EBIC   :822   OBS:822   Min.   :14.00   1/2:230     Both:531   I/II:333  
#>  APOE   :  0   RCT:  0   1st Qu.:24.00   3  :198     None:209   III : 82  
#>  CSTAT  :  0             Median :37.50   4  :113     One : 82   IV/V:407  
#>  HIT I  :  0             Mean   :41.79   5/6:281                          
#>  HIT II :  0             3rd Qu.:59.00                                    
#>  NABIS  :  0             Max.   :92.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah             edh         
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.00000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.00000  
#>  Median :0.0000   Median :0.0000   Median :0.0000   Median :0.00000  
#>  Mean   :0.2871   Mean   :0.2445   Mean   :0.4136   Mean   :0.09246  
#>  3rd Qu.:1.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.00000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.00000  
#>                                                                      
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.3418  
#>  3rd Qu.:1.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: HIT I
#>       name      type          age        motor_score  pupil        ct     
#>  HIT I  :350   OBS:  0   Min.   :14.00   1/2:163     Both:232   I/II:127  
#>  APOE   :  0   RCT:350   1st Qu.:21.00   3  : 54     None: 67   III : 79  
#>  CSTAT  :  0             Median :34.00   4  : 56     One : 51   IV/V:144  
#>  EBIC   :  0             Mean   :35.49   5/6: 77                          
#>  HIT II :  0             3rd Qu.:47.00                                    
#>  NABIS  :  0             Max.   :71.00                                    
#>  (Other):  0                                                              
#>      hypox          hypots             tsah             edh      
#>  Min.   :0.00   Min.   :0.00000   Min.   :0.0000   Min.   :0.00  
#>  1st Qu.:0.00   1st Qu.:0.00000   1st Qu.:0.0000   1st Qu.:0.00  
#>  Median :0.00   Median :0.00000   Median :0.0000   Median :0.00  
#>  Mean   :0.18   Mean   :0.05429   Mean   :0.3257   Mean   :0.18  
#>  3rd Qu.:0.00   3rd Qu.:0.00000   3rd Qu.:1.0000   3rd Qu.:0.00  
#>  Max.   :1.00   Max.   :1.00000   Max.   :1.0000   Max.   :1.00  
#>                                                                  
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2829  
#>  3rd Qu.:1.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: HIT II
#>       name      type          age       motor_score  pupil        ct     
#>  HIT II :819   OBS:  0   Min.   :15.0   1/2:280     Both:583   I/II:345  
#>  APOE   :  0   RCT:819   1st Qu.:22.0   3  :151     None:138   III : 90  
#>  CSTAT  :  0             Median :33.0   4  :181     One : 98   IV/V:384  
#>  EBIC   :  0             Mean   :36.3   5/6:207                          
#>  HIT I  :  0             3rd Qu.:49.0                                    
#>  NABIS  :  0             Max.   :74.0                                    
#>  (Other):  0                                                             
#>      hypox           hypots            tsah             edh        
#>  Min.   :0.000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.000   Median :0.0000   Median :0.0000   Median :0.0000  
#>  Mean   :0.199   Mean   :0.1001   Mean   :0.3272   Mean   :0.1636  
#>  3rd Qu.:0.000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                    
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2295  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: NABIS
#>       name      type          age        motor_score  pupil        ct     
#>  NABIS  :385   OBS:  0   Min.   :14.00   1/2:144     Both:236   I/II: 45  
#>  APOE   :  0   RCT:385   1st Qu.:21.00   3  : 65     None: 99   III :204  
#>  CSTAT  :  0             Median :30.00   4  : 76     One : 50   IV/V:136  
#>  EBIC   :  0             Mean   :31.82   5/6:100                          
#>  HIT I  :  0             3rd Qu.:40.00                                    
#>  HIT II :  0             Max.   :68.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :0.0000   Median :0.0000  
#>  Mean   :0.3299   Mean   :0.1558   Mean   :0.4779   Mean   :0.1325  
#>  3rd Qu.:1.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2623  
#>  3rd Qu.:1.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: PEG
#>       name       type           age        motor_score  pupil        ct     
#>  PEG    :1510   OBS:   0   Min.   :15.00   1/2:655     Both:787   I/II:576  
#>  APOE   :   0   RCT:1510   1st Qu.:20.00   3  :165     None:564   III :345  
#>  CSTAT  :   0              Median :27.00   4  :334     One :159   IV/V:589  
#>  EBIC   :   0              Mean   :30.44   5/6:356                          
#>  HIT I  :   0              3rd Qu.:38.00                                    
#>  HIT II :   0              Max.   :86.00                                    
#>  (Other):   0                                                               
#>      hypox            hypots            tsah             edh         
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.00000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.00000  
#>  Median :0.0000   Median :0.0000   Median :0.0000   Median :0.00000  
#>  Mean   :0.2199   Mean   :0.1695   Mean   :0.4113   Mean   :0.09801  
#>  3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.00000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.00000  
#>                                                                      
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2397  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: PHARMOS
#>       name      type          age        motor_score  pupil        ct     
#>  PHARMOS:856   OBS:  0   Min.   :16.00   1/2:134     Both:667   I/II:429  
#>  APOE   :  0   RCT:856   1st Qu.:23.00   3  :262     None: 37   III :205  
#>  CSTAT  :  0             Median :33.00   4  :225     One :152   IV/V:222  
#>  EBIC   :  0             Mean   :35.01   5/6:235                          
#>  HIT I  :  0             3rd Qu.:45.25                                    
#>  HIT II :  0             Max.   :66.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah            edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :1.000   Median :0.0000  
#>  Mean   :0.2477   Mean   :0.1542   Mean   :0.597   Mean   :0.1939  
#>  3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:1.000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.000   Max.   :1.0000  
#>                                                                    
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.1694  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: SAP
#>       name      type          age        motor_score  pupil        ct     
#>  SAP    :919   OBS:  0   Min.   :15.00   1/2:264     Both:639   I/II:400  
#>  APOE   :  0   RCT:919   1st Qu.:23.00   3  :146     None:155   III :151  
#>  CSTAT  :  0             Median :32.00   4  :223     One :125   IV/V:368  
#>  EBIC   :  0             Mean   :35.63   5/6:286                          
#>  HIT I  :  0             3rd Qu.:47.00                                    
#>  HIT II :  0             Max.   :71.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :0.0000   Median :0.0000  
#>  Mean   :0.1371   Mean   :0.1523   Mean   :0.4418   Mean   :0.2057  
#>  3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2307  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: SKB
#>       name      type          age        motor_score  pupil       ct    
#>  SKB    :126   OBS:  0   Min.   :16.00   1/2:56      Both:81   I/II:54  
#>  APOE   :  0   RCT:126   1st Qu.:20.00   3  :31      None:28   III :40  
#>  CSTAT  :  0             Median :27.00   4  :16      One :17   IV/V:32  
#>  EBIC   :  0             Mean   :30.61   5/6:23                         
#>  HIT I  :  0             3rd Qu.:39.00                                  
#>  HIT II :  0             Max.   :70.00                                  
#>  (Other):  0                                                            
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:1.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :1.0000   Median :0.0000  
#>  Mean   :0.2937   Mean   :0.1905   Mean   :0.7857   Mean   :0.1111  
#>  3rd Qu.:1.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2698  
#>  3rd Qu.:1.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: SLIN
#>       name      type          age        motor_score  pupil        ct     
#>  SLIN   :409   OBS:  0   Min.   :15.00   1/2: 55     Both:316   I/II:154  
#>  APOE   :  0   RCT:409   1st Qu.:21.00   3  : 91     None: 16   III : 94  
#>  CSTAT  :  0             Median :28.00   4  :127     One : 77   IV/V:161  
#>  EBIC   :  0             Mean   :32.35   5/6:136                          
#>  HIT I  :  0             3rd Qu.:43.00                                    
#>  HIT II :  0             Max.   :79.00                                    
#>  (Other):  0                                                              
#>      hypox             hypots            tsah           edh        
#>  Min.   :0.00000   Min.   :0.0000   Min.   :0.00   Min.   :0.0000  
#>  1st Qu.:0.00000   1st Qu.:0.0000   1st Qu.:1.00   1st Qu.:0.0000  
#>  Median :0.00000   Median :0.0000   Median :1.00   Median :0.0000  
#>  Mean   :0.05868   Mean   :0.1369   Mean   :0.78   Mean   :0.1516  
#>  3rd Qu.:0.00000   3rd Qu.:0.0000   3rd Qu.:1.00   3rd Qu.:0.0000  
#>  Max.   :1.00000   Max.   :1.0000   Max.   :1.00   Max.   :1.0000  
#>                                                                    
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2298  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: TCDB
#>       name      type          age        motor_score  pupil        ct     
#>  TCDB   :603   OBS:603   Min.   :16.00   1/2:243     Both:299   I/II:219  
#>  APOE   :  0   RCT:  0   1st Qu.:21.00   3  :105     None:249   III :119  
#>  CSTAT  :  0             Median :26.00   4  :121     One : 55   IV/V:265  
#>  EBIC   :  0             Mean   :32.97   5/6:134                          
#>  HIT I  :  0             3rd Qu.:40.00                                    
#>  HIT II :  0             Max.   :93.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :0.0000   Median :0.0000  
#>  Mean   :0.1808   Mean   :0.2371   Mean   :0.4428   Mean   :0.1045  
#>  3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.4378  
#>  3rd Qu.:1.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: TINT
#>       name       type           age        motor_score  pupil        ct     
#>  TINT   :1118   OBS:   0   Min.   :14.00   1/2:141     Both:807   I/II:474  
#>  APOE   :   0   RCT:1118   1st Qu.:21.00   3  :237     None:138   III :221  
#>  CSTAT  :   0              Median :30.00   4  :327     One :173   IV/V:423  
#>  EBIC   :   0              Mean   :33.61   5/6:413                          
#>  HIT I  :   0              3rd Qu.:45.00                                    
#>  HIT II :   0              Max.   :79.00                                    
#>  (Other):   0                                                               
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :1.0000   Median :0.0000  
#>  Mean   :0.1592   Mean   :0.1404   Mean   :0.5259   Mean   :0.1655  
#>  3rd Qu.:0.0000   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2487  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: TIUS
#>       name       type           age        motor_score  pupil        ct     
#>  TIUS   :1041   OBS:   0   Min.   :14.00   1/2:152     Both:708   I/II:463  
#>  APOE   :   0   RCT:1041   1st Qu.:23.00   3  :132     None:211   III :198  
#>  CSTAT  :   0              Median :30.00   4  :300     One :122   IV/V:380  
#>  EBIC   :   0              Mean   :32.78   5/6:457                          
#>  HIT I  :   0              3rd Qu.:41.00                                    
#>  HIT II :   0              Max.   :77.00                                    
#>  (Other):   0                                                               
#>      hypox            hypots          tsah             edh         
#>  Min.   :0.0000   Min.   :0.00   Min.   :0.0000   Min.   :0.00000  
#>  1st Qu.:0.0000   1st Qu.:0.00   1st Qu.:0.0000   1st Qu.:0.00000  
#>  Median :0.0000   Median :0.00   Median :0.0000   Median :0.00000  
#>  Mean   :0.2795   Mean   :0.22   Mean   :0.4284   Mean   :0.08646  
#>  3rd Qu.:1.0000   3rd Qu.:0.00   3rd Qu.:1.0000   3rd Qu.:0.00000  
#>  Max.   :1.0000   Max.   :1.00   Max.   :1.0000   Max.   :1.00000  
#>                                                                    
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.2161  
#>  3rd Qu.:0.0000  
#>  Max.   :1.0000  
#>                  
#> ------------------------------------------------------------ 
#> impact$name: UK4
#>       name      type          age        motor_score  pupil        ct     
#>  UK4    :791   OBS:791   Min.   :14.00   1/2:198     Both:433   I/II:271  
#>  APOE   :  0   RCT:  0   1st Qu.:22.00   3  :231     None:243   III :155  
#>  CSTAT  :  0             Median :36.00   4  :141     One :115   IV/V:365  
#>  EBIC   :  0             Mean   :39.64   5/6:221                          
#>  HIT I  :  0             3rd Qu.:55.00                                    
#>  HIT II :  0             Max.   :87.00                                    
#>  (Other):  0                                                              
#>      hypox            hypots            tsah             edh        
#>  Min.   :0.0000   Min.   :0.0000   Min.   :0.0000   Min.   :0.0000  
#>  1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.:0.0000  
#>  Median :0.0000   Median :0.0000   Median :1.0000   Median :0.0000  
#>  Mean   :0.2566   Mean   :0.2642   Mean   :0.5183   Mean   :0.1429  
#>  3rd Qu.:1.0000   3rd Qu.:1.0000   3rd Qu.:1.0000   3rd Qu.:0.0000  
#>  Max.   :1.0000   Max.   :1.0000   Max.   :1.0000   Max.   :1.0000  
#>                                                                     
#>       mort       
#>  Min.   :0.0000  
#>  1st Qu.:0.0000  
#>  Median :0.0000  
#>  Mean   :0.4539  
#>  3rd Qu.:1.0000  
#>  Max.   :1.0000  
#>                  

# Plot the distribution of age by study
library(ggplot2)
e <- ggplot(impact, aes(x = name, y = age))
e + geom_violin(aes(fill = type), trim = FALSE)  + 
    theme(axis.text.x = element_text(angle = 45)) + 
    xlab("Study")