3149 Measuring vitamin D post hip fracture—should we test or just treat? Lessons learnt from an ortho-geriatric rehab unit

Introduction Plasma 25(OH)D is commonly tested following hip fracture. The National Osteoporosis Society recommends against routine testing in these patients as vitamin D is often co-prescribed with anti-resorptive agents, making vitamin D testing unnecessary. Our median reporting time for plasma 25(OH)D is 11.5 days, costing around £7/unit. High dose, rapid vitamin D loading costs £1.34. So, is vitamin D testing in these patients cost-effective and does it add to our clinical decision-making? Method Records of 72 discharges from our ortho-geriatric unit over 3 months were reviewed for admission serum calcium, creatinine clearance, PTH and vitamin D. Vitamin D prescription regimes were reviewed. Results 100% of patients had plasma 25(OH)D checked. Mean plasma 25(OH)D was 44.8 (range < 5–106.6). 23 patients were vitamin D deficient (32%), 23 insufficient (32%) and 26 replete (36%). 100% of patients with vitamin D deficiency and 91.3% with insufficiency received rapid high dose vitamin D loading regime (150,000–200,000 units over 1–7 days). 53.8% of vitamin D replete patients were prescribed a high dose vitamin D regime (n = 14) but 3 were switched to low dose when levels returned as normal. 12 patients with an early normal plasma 25(OH)D were prescribed Adcal D3 or low dose colecalciferol. Conclusions 58 patients (80.5%) were prescribed rapid high dose vitamin D regimes, the majority of whom were vitamin D deficient or insufficient. Only 3 patients were switched and a further 12 started on low dose vitamin D based on a normal plasma 25(OH)D result. Plasma 25(OH)D resulted in a change in vitamin D regime in only 20.8% of patients. When comparing the cost of the test to that of the treatment regime, we would argue that serum calcium/PTH are more cost-effective and stronger predictors of who requires a lower dose vitamin D dose regime (e.g. in hyperparathyroidism) than plasma 25(OH)D.