Clinical notes as indicators for vitamin B12 levels via text data mining

Abstract

Aim The utility of high volume vitamin B12 (B12) request has been questioned. We reviewed the relationship between clinical notes provided and B12 levels. Methods Request forms for total B12 over 2007-2011 were reviewed. We focussed on 90,000 episodes where holotranscoba-lamin (holoTC) was measured (Abbott AxSym), and two thirds of these requests had clinical notes provided. Results The clinical note most predictive of holoTC deficiency (≤20pmol/L) was ‘vegetarian’ or ‘vegan’ (odds ratio — 2.2 versus requests without any clinical notes). Other clinical notes predictive of holoTC deficiency were (odds ratio): ‘Crohn’s disease’ (2.0), ‘Falls’ (1.6), ‘Diarrhoea’ (1.4), ‘Weight loss’ (1.4) and ‘Dementia’ (1.3). The least predictive clinical notes in order were: ‘Malaise’ (0.5), ‘Renal disease’ (0.6), ‘Fatigue’ (0.6), ‘Routine’ (0.6), ‘Low haemoglobin’ (0.7) and ‘Check-up’ (0.8). Paradoxically, a clinical note of ‘Low haemoglobin’ was associated high holoTC levels (>80pmol/L) (odds ratio = 1.8). Other notes associated with high holoTC were (odds ratio): ‘Renal disease’ (2.4), ‘Coeliac disease’ (2.3), ‘Anaemia’ (1.9) and ‘Low B12’ (1.8), suggesting that these notes often indicate B12 supplementation. Discussion The association of clinical notes with B12 levels are clinically plausible. This novel approach provides objective evidence for developing strategies for appropriate use of pathology testing.