We found that the commonest reasons that patients give for missing appointments are mistakes and misunderstandings (frequently by the practice) and forgetfulness. The majority of patients who missed an appointment consulted their GP within three months, with most of these consulting for the original problem that they were originally going to present. The low number of matched case-control pairs led to the comparisons between those who missed appointments and those who did not having wide confidence intervals which included 1.0, and despite some large effect sizes, for example a 33% reduced odds for a woman compared to a man of missing an appointment, these data cannot exclude the role of chance. However, reporting these results is important since the low response rate has important implications for future work in this area and highlights the importance of developing ways of engaging the disengaged in primary care research.
Study strengths and limitations
The age distribution of the comparison group was in keeping with national figures for those attending general practice, indicating that the practices participating in this study are representative of general practice as a whole . One of the main strengths of this study is the investigation of an area which is important to primary care but which has been rarely investigated, perhaps because of anticipated difficulties. Further, we have attempted to improve upon previous studies with a prospective design, comparisons with a comparison group and use of a neutral place for correspondence. The main weakness of the study is the low response and the differential response between patients and the comparison group. A selection bias may exist between those who responded with respect to the outcomes of interest; this may be because of both social desirability bias and post-hoc rationalisations in their written responses. Responders may be over-represented by those whose missed appointment was a genuine practice mistake, and those who were less obliged to operate within the practices' booking systems being less likely to respond. Assuming that all 68% of non-responders did not miss their appointment because of forgetfulness or practice misunderstandings, then interventions aimed at dealing with these problems would only be able to reduce the overall missed appointment rate by a small amount.
Reasons for missing appointments
Within the category 'misunderstandings and mistakes', the largest sub-category was 'by the practice'. Further, in the response to the pre-defined categories, 30% stated that they had tried to cancel their appointment. A small number of patients reported that they had either cancelled their appointment or indeed kept their appointment. These findings were not verified by the medical records, therefore it is difficult to know whether these represent practice mistakes of post-hoc rationalisations of behaviour. Whilst this may reflect post-hoc rationalisations or may be exaggerated by selection bias, there is consistency between the two questions and the results suggest that improvements in practice communication systems could reduce missed appointments. Forgetfulness was another important cause. One practice strategy that may reduce this problem would be the use of aide-memoirs. However, intervention studies are required to demonstrate their effect. In a parallel study we have assessed the perceptions of primary care health professionals of the reasons for missing appointments . Interestingly, practice staff tended to blame patients for missed appointments and dismissed the idea that practice factors may contribute. The results of this study suggest that practice factors contribute to some missed appointments suggesting that considering practice level interventions (e.g. making it easier to cancel appointments, and greater convenience of appointment times) may be useful.
Consequences of missed appointments
The finding that virtually all patients who missed an appointment did subsequently consult within a three month period has not been previously demonstrated. In fact, over half of those who responded consulted within the following two weeks of the missed appointment. Again selection bias may have influenced this result if those who did not respond were different to those who did and were less likely to subsequently attend. This study was unable to determine whether those with psychiatric morbidity are more likely to miss appointments; and whilst further research in this area is required to determine this, a recent paper has found that psychological morbidity did affect the likelihood of missing appointments .
Engaging with the disengaged
There are several implications of these results for future research. This work adds to the literature confirming that more work needs to be done to engage people who miss appointments with research in a more meaningful way. Creative approaches, in terms of accessing and engaging patients who have missed appointments in research, and of using appropriate methodologies to answer important questions need developing; qualitative methods may be best at exploring the phenomenon from user perspectives and would help to unravel the complex relationships surrounding consultation etiquette and patients' and practitioners' behaviour. Closer involvement of users might inform this process , as may the use of inducements. One option would be to recruit patients when they next consult in primary care, as we have shown the vast majority do consult again soon. If research was then conducted in a neutral environment, the use of practice members to recruit participants need not bias the responses. The lessons that we have learned have implications for future research for others who are developing work with other 'disengaged' or potentially vulnerable groups of patients. There is still a need for health professionals to maintain their concern for the health of patients who miss appointments, since this study does not exclude the possibility that they may have unmet mental health problems.