Ni Mhurchu et al. BMC Public Health 2010, 10:738 http://www.biomedcentral.com/1471-2458/10/738 Table 1 Primary and secondary outcome measures Outcome Attendance Academic achievement Self-reported grades Sense of belonging Psychosocial function Hunger Dietary habits Food security Instrument/Method Recorded school attendance Literacy and numeracy Study questionnaire [24] PISA 2000 Sense of Engagement Scale [25] Strengths and Difficulties Questionnaire [26,27] “Freddy” [28] Dietary Habits Questionnaire (breakfast only) [29,2] CCHIP scale [30,31] Collected from Schools Schools Students Students (Year 4 and above) Teachers Students Parents Parents Page 4 of 6 are read to younger students or those who have diffi- culty understanding. Primary outcome Attendance is defined as total number of half days stu- dents are present at school (including those slightly late for the morning or afternoon session e.g. due to a medi- cal appointment). The main measure of attendance is the proportion of students achieving a school attendance rate of 95% or higher, which equates to students missing less than 2-3 days per school term. Other attendance outcomes are number of late, sick or medical days, justi- fied absences (e.g. bereavement leave), and unjustified absences (truancy). Attendance data are recorded by schools in the usual way and extracted for data collec- tion at the end of each school term. Secondary outcomes Academic achievement is assessed using numeracy and literacy data collected by schools using standardised tests administered to all students during the year. New Zealand schools use a limited range of tests to assess numeracy and literacy (e.g., asTTle, PAT, SEA), usually during terms 1 and 4. Data will be collated, integrated, and analysed by an expert in academic assessment (JH), taking into account any maturation effect, thus permit- ting assessment on the same scale. Self-reported grades (i.e., children’s perceived aca- demic competence) are a determinant of actual aca- demic performance in core subjects [22,23]. Perceived academic competence is measured by asking students to make a realistic assessment of their reading ability in comparison to other students in their year at school, with five response options ranging from 1 (not very well) to 5 (very well) [24]. Students’ sense of belonging is measured using the PISA 2000 Student Engagement Questionnaire, which consists of six statements with four response options ranging from strongly disagree to strongly agree [25]. It measures whether students feel comfortable and as if they belong at school, as well as their relationship with other students. Although designed for use with 15 year-old students, it has a readability level appropriate for younger students. Only students in Year 4 or above (approximately 8 years or older) complete this questionnaire. The Strengths and Difficulties Questionnaire (SDQ) [26,27] assesses students’ behaviour, emotions and rela- tionships and is completed by the student’s teacher. The SDQ consists of 25 items related to five dimensions: hyperactivity/inattention, emotional symptoms, conduct problems, peer relationship problems, and prosocial behaviour. Temporary hunger levels are assessed using a modified version of “Freddy”, an analogue scale (1-15) for mea- suring fullness or satiety in children [28]. Freddy has been validated for use in the United States and was pre- tested with decile 1 New Zealand primary schoolchil- dren aged 6-11 years (n = 21) prior to the start of the study. Pre-testing demonstrated expected increases in mean satiety ratings between beginning, middle and completion of breakfast. Furthermore the instrument showed good test-retest reliability: median scores at the beginning of breakfast were 6.4 on day 1 and 5.9 on day 2, whilst median scores at the end were 14.5 and 14.4 respectively. There were no significant differences in scores between the two days (p-values > 0.7). Students’ dietary habits over the past week are assessed using questions from previous national surveys [29,2]. Three questions assess how often students eat breakfast, where they eat breakfast, and where they source food for breakfast. The CCHIP scale [30,31] is used to assess food secur- ity status. CCHIP was chosen because this instrument differentiates between household and child food security, whereas most other measures focus on household food security. The scale consists of eight questions, two about the household, two about adults in the household, and four about the child/children in the household. Process evaluation A concurrent process evaluation will collect information from school breakfast providers, schools, and parents on their perceptions of the breakfast programme and any challenges associated with its implementation and