Table 2 Characteristics of the cohort

 Intoxication/Mental and behavioural disorders due to alcohol use (F10)

3608

49.5%

 Poisoning by drugs, medicaments and biological substances (T36–T50)

1382

19.0%

 Head Injury (S00–S09)

885

12.1%

 Toxic effect of alcohol (T51)

579

7.9%

 Other physical injury (S10-S99, T00-T35)

378

5.2%

 Syncope and collapse (R55)

112

1.5%

 Diseases of the digestive system (K00-K93)

50

0.7%

 Digestive system and abdomen conditions (R10–R19)

43

0.6%

 Convulsions (R56)

27

0.4%

 Diabetes mellitus (E10–E14)

22

0.3%

 Epilepsy (G40)

19

0.3%

 Intoxication/Mental and behavioural disorders due to (non-alcoholic) psychoactive substance use (F11-F19)

16

0.2%

 Other primary diagnosis

165

2.3%

 Males

3553

48.8%

 Females

3733

51.2%

 White

3977

54.6%

 Asian or Asian British

64

0.9%

 Black or Black British

54

0.7%

 Ethnicity mixed or other

96

1.3%

 Ethnicity not known or not stated

3095

42.5%

 Aged 12

332

4.6%

 Aged 13

923

12.7%

 Aged 14

1504

20.6%

 Aged 15

1574

21.6%

 Aged 16

925

12.7%

 Aged 17

896

12.3%

 Aged 18

1132

15.5%

 Patient also had self-harm diagnosis

1515

20.8%

 Patient also had injury diagnosis

1146

15.7%

 Patient also had other substance use diagnosis

435

6.0%

 Patient also had assault diagnosis

321

4.4%

 Patient also had other mental health diagnosis

343

4.7%

 Patient also had “undetermined intent” diagnosis

70

1.0%

 Didn't return after index episode

6609

90.7%

 Returned only once (i.e., two visits in total)

501

6.9%

 Returned only twice (three visits in total)

116

1.6%

 Returned only three times (four visits in total)

29

0.4%

 Returned only four times (five visits in total)

15

0.2%

 Returned only five times (six visits in total)

5

0.1%

 Returned six or more times (seven or more visits)

11

0.2%