Table 1 Content of the baseline, diary and follow-up questionnaire

 Socio-demographics

X

X

 Smoking details and history

X

X

X

 Quit attempt history

X

 Number of cigarettes smoked

X

X

X

X

X

 Hiding of smoking

X

X

 Duration of abstinence

X

X

 Perceived frequency of smoking-related conflicts (SRC)

X

X

X

X

 Relationship satisfaction

X

X

X

X

X

X

 Smoking dependence

X

X

X

X

 Smoking now compared to before quit attempt

X

X

 Details of partner contact

X

X

 Partner responses

X

X

 Partner responses to difficult moment

X

X

 Attitude towards smoking

X

X

 Affect (PANAS)

X

X

X

X

 Opinion partner about quitting/smoking behaviour

X

X

X

 Influence of SRC

X

 Perceived susceptibility

X

X

X

X

 Perceived relatedness

X

X

X

X

 Self-compassion towards relapse

X

X

X

X

 Intention to quit

X

X

 Taking steps to go smoking

X

 Use of smoking replacement

X

X

X

X

 Difficulty quitting

X

X

 Adherence to planning

X

X

X

X

 Helpfulness of planning

X

X

X

X

 Conflicts not related to smoking

X

X

 Interference of quitting with relationship

X

X

 Details social contacts

X

X

 Interference of quitting with social contact

X

 Other health behaviours

X

X

 SRC initiator

X

X

 SRC recentness

X

X

 SRC pattern

X

X

 Partner interaction questionnaire

X

X

 Details most difficult moment

X

X

 Distraction from smoking

X

X

 Motivation to remain quit

X

 Evaluation of diary

X

X

X

X

 Self-efficacy to quit

X

X

X

 Daily activities

X

X

 Role of smoking in break-up

X

X

 Influence of plan on relationship

X

X

 Missing smoking

X