1. Predicting risks of asthma recurrence Stephen Watt Consultant in Respiratory and Hyperbaric Medicine Aberdeen Royal Infirmary

2. Asthma Hazards at work Inability to do job (restricted work capacity) Frequent periods of illness Sudden incapacity to do critical tasks Exposure to sensitisers Outcome of acute episodes in remote locations

3. Asthma Assessment of fitness for work Certificate of fitness – misleading and misunderstood – often rigid application of guideline Medical assessment = risk assessment – transparent – logical – understood by patients

4. Asthma Definition – no gold standard Clinical diagnosis – Cough, wheeze, breathlessness, chest tightness + variable airflow obstruction – Pathology involves airway hyper- responsiveness and inflammation Very common

5. Asthma in Children Diagnosis – Cough, SOB occur with viral infections – Frequency, diurnal variation, triggers, atopy, family history, response to Rx Prognosis – Age > 2 - < 2 – Sex – Female > Male – Frequency of episodes – Severity – Atopy – Family history – Abnormal lung functuion

6. Asthma in Adults Patterns of disease – Episodic atopy, infection, exercise – Persistent Severity – Mild (acute episode history) – Moderate – Severe (therapy history) – Brittle – Cough variant Impact of therapy

7. Prevalence Problems with diagnosis – Wheeze ever, episode in last year, treatment = 8.1% – 2001 health survey Wheeze in last year 15-20% age up to 55 Diagnosis of asthma 10-15% age up to 55 Very common

8. Asthma mortality Approx 1200 asthma deaths in UK pa Age specific mortality – Children and adults 1 per 100,000 – Adults 45 – 64 = 2 per 100,000 – Adults > 65 = 10 per 100,000

11. Asthma morbidity Is survival dependent on benefit of medical care?

13. Asthma morbidity Asthma is common cause for hospital admission But – Multiple admissions – Cause for admission Poor compliance, panic, co-morbidity – Small number are life threatening

14. Predicting the risk Risk in this age group is very small Risk factors for death – Age – Poor lung function – Co-morbidity – Previous severe episodes (hospital admissions) – Previous near fatal episode – Poor compliance with treatment – No diagnosis Proportion of deaths occur without diagnosis

15. Assessing the risk Medical history – Age of onset – Severity (current treatments) – Symptoms (when well and when unwell) – Frequency of episodes – Control of episodes (Self management) – Monitoring PEF (where appropriate) Lung function

16. November 2008 Lung function tests FEV1 – best of three satisfactory attempts – most reproducible test – SD is 0.5 litres Normality 95% confidence limits = predicted normal +- 1.67 * 0.5 Percent predicted value not helpful! – remember ethnic correction factors

17. What can asthmatics do? Almost all jobs dependent on assessment – Manual labouring – Athletics – Police – (Firemen) – (Diver)

19. Where do asthmatics work? Altitude Offshore Polar regions