Factors correlating to the propensity of general practitioners to substitute borderline vitamin B12 deficiency

Objective: This study aims to identify factors which correlate to the propensity of general practitioners (GPs) to prescribe supplementation for borderline vitamin B12 deficiency. Design: Cross-sectional surveys were distributed in person. Setting: Conferences held in Cairns, Palm Cove Beach, Mt Isa; educational meetings in Atherton; and meetings with individual general practices within the Cairns and Hinterland region. All located in Queensland, Australia. Subjects: 128 practicing GP specialists and registrars (practitioners in training). Main outcome measures: Responses to the Likert scale statements with its five options scaling from 'strongly disagree' to 'strongly agree' were recoded to have binary outcomes for analysis. Results: A survey response rate of 89% was achieved. Participants who felt patient demands influence the management of borderline vitamin B12 deficiency were more likely to prescribe supplementation (OR 2.4, p=0.037). Participants who perceived an overuse of vitamin B12 were less likely to prescribe B12 (OR 0.39, p=0.019). Participants who often saw patients with vitamin B12 deficiency were less likely to request for the complementary biomarkers plasma methylmalonic acid or total homocysteine (OR 0.41, p=0.045). Conclusions: The identified disparity to prescribe vitamin B12 for borderline deficiency may be described as an attempt in the GP collective to seek a balance between being the patient's or the society's doctor. We propose that relevant authorities try to reduce this disparity by describing a management strategy for borderline vitamin B12 deficiency.