The emotional impact of screening for lung cancer

Lung cancer is the most commonly diagnosed cancer and the most common cause of cancer related death worldwide. Population-based lung cancer screening programmes have been initiated in the USA and could soon be implemented in other countries. The overarching purpose of this thesis was to explore the emotional impact of lung cancer screening. The research was conducted as part of a clinical trial that was investigating the effectiveness of a blood autoantibody test, EarlyCDT®-Lung, in identifying individuals at the risk of lung cancer. A systematic review was conducted that aimed to identify factors associated with the emotional impact of screening for lung cancer. Participants with indeterminate test results, current smokers and females were more likely to experience negative non-specific and specific emotional outcomes. In addition to highlighting several key factors associated with higher levels of emotional distress following screening, factors that warranted further research were also identified. Such factors included age, education level, marital status, ethnic origin, and perceived risk of developing lung cancer. Finally, important methodological and theoretical limitations in the literature were identified. One key methodological limitation was that no studies measured positive emotional outcomes. A longitudinal study was conducted exploring the impact of lung cancer screening on positive affect, negative affect, lung cancer worry and distress specific to screening for lung cancer. Participants from each of the EarlyCDT®-positive, EarlyCDT®-negative, and control groups completed questionnaires containing emotional outcome measures at pre-randomisation and then at one, three, six and 12 months post randomisation. Scores for each outcome measure were described by groups over time and multilevel regression modelling was used to compare scores over time within and between groups. Results were reassuring as screening was found to have no clinically important impact on positive affect, negative affect, frequency of lung cancer worry or impact of lung cancer worry on mood and ability to perform daily activities. Although screening specific distress in the EarlyCDT®-positive group was significantly higher than that of the EarlyCDT®-negative group, it did reduce over time. Statistically significant and clinically important increases in the proportion of participants reporting anxiety about the results of future tests/treatments were identified. As a result of this finding, a further study was carried out to identify factors that could influence an individual’s level of anxiety about the results of future tests/treatment. Participants more at risk of reporting anxiety about the results of future tests/treatment were younger participants, non-white participants, current smokers and participants who did not own or have a mortgage on their home. Psychological variables associated with increased anxiety were: higher general anxiety scores, higher depression scores, higher negative affect scores, participants who reported that they were upset when they thought about their risk of lung cancer, participants who were worried about getting lung cancer, and those who reported the highest impact of lung cancer worry on mood and ability to perform daily activities. The final chapter of this thesis presents the results of a randomised controlled trial embedded within the emotional outcomes study (described above), which evaluated the effect of timing of monetary incentives (£5 voucher sent with questionnaire vs. £5 voucher sent on receipt of questionnaire) on the following outcomes: study participation rates, questionnaire response rates over time, the number of reminders sent and the completeness of returned questionnaires over time. Previous research had found that monetary incentives were useful in increasing response rates in clinical trials. Results from this trial extended the evidence base by showing that the timing of monetary incentives makes no difference to the above outcomes. In each chapter the findings of this thesis are discussed in terms of their contribution to knowledge. Recommendations for future research and clinical practice are also made within each chapter