Attention-deficit/hyperactivity disorder and serial missed appointments in general practice.

Missingness' in health care has recently been flagged as a major challenge due to associations between missing multiple appointments and poor long-term outcomes. Patients with a range of mental health diagnoses, for example, can have difficulties maintaining continuity of care and miss appointments with adverse consequences, including increased mortality. This is especially problematic for those with a diagnosis of ADHD because it is relatively common, with an estimated prevalence of 2-5% of the population. This study therefore aimed to a) establish the prevalence of recorded ADHD b) characterise and compare individuals with and without ADHD in terms of health and social variables, and c) assess whether ADHD was associated with an increased risk of missing scheduled appointments in general practice. Using administrative data from 136 Scottish general practices, patients with at least one GP appointment between September 2013-2016 we identified those with ADHD based on diagnoses and prescribing data. Each case was matched (sex and age) to five randomly selected GP attendees. Groups were compared regarding health, social status and missed appointments. All results were stratified by age <18 or ≥18 years. Among 824,374 GP patients we identified 2,452 with a record of ADHD (0.8% among those <18 years; 0.2% age ≥18 years). ADHD was associated with living in socially deprived areas of Scotland, and multimorbidity was more frequent in adults (p<0.01). Adjusting for the number of total appointments made, ADHD was associated missing GP appointments (<18 years: OR = 1.6, 95%CI = 1.4-1.9; ≥18 years: OR = 1.9, 95%CI = 1.7-2.2). Annually 21% in those <18 and 38% of those age ≥18 years missed at least one GP appointment. The prevalence of recorded ADHD in Scottish general practice is low but comparable to other studies using data derived from medical records. More importantly, this is the first study to demonstrate an association between ADHD and missingness in general practice. The findings have important implications for health services concerning the early diagnosis and treatment of ADHD.