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For Primary Care| View from the ground

How a Guideline on Vitamin B12 Deficiency in Adults Prompted an Audit to Improve Treatment

View From the Ground, by Dr Jan O D Jablonski

Every day, GPs have to deal promptly with many lab results, to prevent getting buried under piles of paperwork. Sometimes a new guideline comes along and helps to streamline the processing of these results. This is what happened with Vitamin B12, treatment of deficiency in adults,1 guidance from the NHS Greater Glasgow and Clyde Area Drug and Therapeutics Committee, which we quickly implemented in our health board.

Vitamin B12 is a water-soluble vitamin, a cofactor in both DNA synthesis and fatty and amino acid metabolism, and is crucial for the normal functioning of the nervous system.2 It binds to intrinsic factor (IF) secreted by gastric parietal cells (PC) and is absorbed in the terminal ileum.2 Given that food-based malabsorption associated with gastric atrophy—which can be age related or due to proton pump inhibitor (PPI) use—is the likely cause of a large proportion of cases of subclinical vitamin B12 deficiency,1 it was hypothesised that a significant number of patients at the practice were receiving intramuscular (IM) vitamin B12 injections unnecessarily. For this reason, I carried out an audit of these patients.

Using the EMIS platform, a search was performed in March 2019 to find all patients at the practice who were being prescribed IM vitamin B12, and the information was exported to a spreadsheet. Then, EMIS, Docman, and Clinical Portal records were meticulously searched to see whether patients receiving IM vitamin B12 were having the following tests:

  • vitamin B12 and folate levels
  • IF antibodies
  • PC antibodies
  • a thyroid function test (TFT) within the previous 12 months for patients with a positive test for IF and/or PC antibodies 
  • a coeliac test for total immunoglobulin A (IgA) and IgA tissue transglutaminase (tTG) for patients with low folate levels.

The reason for carrying out TFTs is that there is a high prevalence of hypothyroidism in patients with pernicious anaemia, and vice versa.3,4 For tTGs, folate deficiency may cause vitamin B12 levels to be low and, although dietary deficiency is the most common cause of low folate, all patients with combined low folate and vitamin B12 should have a one-time tTG, regardless of the presence or absence of malabsorption symptoms.5

When the data collected in March 2019 was tabulated, it became apparent that not everyone was aware of, or following, this new guideline. I presented my findings at our practice meeting. I then saved a PDF copy of the guideline to a shared folder on the practice drive—easily accessible to all practice staff—and directed staff to look at its decision algorithm flow chart, which is a useful one-page summary.

An identical search was run in October 2019, which revealed improvements in all five criteria, and the data were presented at a subsequent practice meeting. For example, 100% of patients who were being prescribed IM vitamin B12 had had their B12 and folate levels checked, and more than 90% of patients had had their IF and PC antibodies tested.

For those in whom both the IF and PC antibody tests were negative, injections were stopped; the patient received a text message or phone call and a written letter explaining why this was happening, which included advice that vitamin B12 levels were to be rechecked 3 months after stopping injections. If levels were normal, then no further action was required. If levels were low, then a month-long trial of oral vitamin B12 was completed and levels were rechecked at the end of this time. If levels were normal at the end of the trial, then oral B12 was stopped and dietary advice was given. If B12 levels were still low, injections were restarted indefinitely. As a result of this process, 57.5% of patients at our practice who were receiving IM vitamin B12 injections (61 out of 106) are no longer receiving them.

Following the audit, I reflected on how this long process could be improved. It is important that practice staff are aware of and using the new guideline, and coding the diagnosis and prescription correctly in patient record systems, such as EMIS. Instead of using multiple EMIS codes for this, I proposed the standard should be: vitamin B12 deficiency; positive for antibodies [PC or IF] as an active problem; this diagnosis is then linked to hydroxocobalamin under medications; followed by a pharmacy text entry specifying annual TFTs due [future date]. For patients needing to receive vitamin B12 without a positive test for antibodies, that part is left blank and the pharmacy text is not used.

Combining the new vitamin B12 guideline, EMIS coding, and some common sense can go a long way in streamlining lab results and improving patient care.

Dr Jan O D Jablonski

GPST3, Kenmure Medical Practice, Bishopbriggs, Glasgow