BACKGROUND-AIM:
The connection between school absenteeism and substance use is well established, particularly for chronic school absenteeism. Truancy - unexcused school absence - has received most attention, being strongly associated with a range of risk behaviours including substance use. Differences in substance use behaviour between students who report truancy and other types of school absenteeism such as for illness have received less attention. This study examines whether smoking and e-cigarette use differs depending on reasons for school absenteeism- truancy, illness, or other reason.

METHODS:
We use data from a nationally representative stratified random sample of (n=5587) 15-18 year olds in Ireland, collected online in 2024 using the European School Survey Project on Alcohol and other Drugs protocol. Respondents were asked if they had ever smoked/used e-cigarettes (ever use) and if yes, their use in the previous 30 days (current use). Three types of school absenteeism were measured by whether respondents answered “yes” to any of these questions “During the LAST 30 DAYS on how many days have you missed one or more lessons?”: “Because of illness”, “Because you skipped or ‘cut’” (truancy), “For other reasons” (6 response categories, never to 7 days or more). Analyses were carried out using SPSS v29.

RESULTS:
School absence on at least one day during the previous 30 days ranged from 62.6% (n=2985) for illness, 60.8% (n=3065) for other reasons, and 23.9% (n=1120) for truancy. For illness, other reasons and truancy respectively, 7.1% (n=340), 6.9% (n=348) and 2.6% (n-124) reported absence on 7 days or more. Prevalence of smoking was 31.2% (n=1,664) ever and 14.2% (n=758) current; and of e-cigarette use 39.3% (n=2,066) ever, and 20.6% (n=1083) current. Those who reported no absences had significantly lower prevalence of smoking and e-cigarette use (p<0.001) than those who reported any absence (one or more days). This was the case for absences for illness, for truancy and for other reasons (p<0.001). In general, more absenteeism was associated with increasingly higher prevalence of ever and current smoking and e-cigarette use. Associations with truancy were most pronounced, with those who reported 7 days or more absenteeism having prevalence of 51.6% (n=63) current smoking and 61.9% (n=73) current e-cigarette use (p<0.001).

CONCLUSIONS:
We find that absence from school for any reason (illness, truancy or other) is associated with higher prevalence of smoking and e-cigarette use, particularly pronounced for absences due to truancy. Absenteeism “for other reasons” needs further examination, being potentially linked to school exclusion, withdrawal, or refusal (including absence due to mental health problems such as anxiety ). Increases in school absenteeism since Covid-19 pandemic have been widely documented and should therefore become a more salient focus in tobacco control research. This potentially hard-to-reach population needs special attention. Health literacy, Providing information to empower people to resist industry tactics and make informed choices.