Research on sickness absence has typically focussed on single diagnoses, despite increasing recognition that long-term health conditions are highly multimorbid and clusters comprising coexisting mental and physical conditions are associated with poorer clinical and functional outcomes. The digitisation of sickness certification in the UK offers an opportunity to address sickness absence in a large primary care population.

Lambeth Datanet is a primary care database which collects individual-level data on general practitioner consultations, prescriptions, Quality and Outcomes Framework diagnostic data, sickness certification (fit note receipt) and demographic information (including age, gender, self-identified ethnicity, and truncated postcode). We analysed 326 415 people's records covering a 40-month period from January 2014 to April 2017.

We found significant variation in multimorbidity by demographic variables, most notably by self-defined ethnicity. Multimorbid health conditions were associated with increased fit note receipt. Comorbid depression had the largest impact on first fit note receipt, more than any other comorbid diagnoses. Highest rates of first fit note receipt after adjustment for demographics were for comorbid epilepsy and rheumatoid arthritis (HR 4.69; 95% CI 1.73–12.68), followed by epilepsy and depression (HR 4.19; 95% CI 3.60–4.87), chronic pain and depression (HR 4.14; 95% CI 3.69–4.65), cardiac condition and depression (HR 4.08; 95% CI 3.36–4.95).

Our results show striking variation in multimorbid conditions by gender, deprivation and ethnicity, and highlight the importance of multimorbidity, in particular comorbid depression, as a leading cause of disability among working-age adults.

To investigate the attitudes to health and work of general practitioners (GPs) with training in occupational medicine (OM) compared with non-OM trained GPs, since the introduction of the fit note.

Changes to the UK sickness certification system since 2010 and the introduction of the fit note required GPs to change their focus to what patients can do, rather than what they cannot do in relation to work. In an effort to reduce the UK sickness absence burden, GPs completion of the fit note should help to keep people in work, or assist patients to return to work as quickly as possible after a period of absence.

Questionnaire data were collected via the 7th National General Practitioner Worklife Survey.

Results indicate that responses from GPs who had undertaken training in OM, and GPs having received some form of work and health training in the 12-month period before the study were associated with significantly more positive attitudes to patients’ returning to work and to the fit note. This study reveals evidence of a difference between trained and non-trained GPs in their attitude to the fit note, and to work and health generally. Further work investigating the effect of specific training in OM on the management and recognition of ill-health by GPs is recommended.