Iron supplementation in Switzerland - A bi-national, descriptive and observational study.

Background: Iron deficiency is the most common nutritional disorder in the world, and it is the only common nutrient deficiency in industrialised nations. It is thought to be the most common cause of anaemia. Use of iron supplementation in Switzerland has not been previously quantified in detail.

Objectives: We quantified use of iron supplementation from Swiss data and compared it with data from the UK. We assessed the frequency of serum ferritin and haemoglobin tests prior to newly started iron therapy to see whether use was based on documented low iron levels or blood parameters, especially in the case of parenteral iron supplementation.

Methods: We conducted a retrospective descriptive study of prescription iron supplementation use, and compared use of oral or parenteral iron drugs between Switzerland (CH) and the UK. We retrieved Swiss data from the Swiss Health Insurance Helsana Group, and UK data were from the Clinical Practice Research Datalink (CPRD). The study period was 2012 to 2014.

Results: The 3-year prevalence of iron supplementation was 9.4% in Switzerland and 4.4% in the UK. Iron use increased slightly between 2012 and 2014 in both countries (CH +0.3%, UK +0.2%). Recorded parenteral iron administration was roughly a thousand times higher in Switzerland (1.9%) than in the UK in 2014. In Switzerland, iron supplements were mostly given to patients aged 20 to 49 years or older than of 80 years. In the UK, iron supplementation was less frequent in younger people, but more prevalent in the elderly. Prior to a first iron prescription, ferritin tests were done more frequently in Switzerland (oral 67.2%, parenteral 86.6%) than in the UK (oral 43.3%, parenteral 65.5%). Haemoglobin was measured before a new parenteral iron therapy rarely in Switzerland (oral 14.9%, parenteral 11.7%), but frequently in the UK (oral 77.4%, parenteral 85.6%).

Conclusions: Iron supplementation is more common in Switzerland than in the UK, particularly parenteral iron supplementation. Haemoglobin measurements prior to a new parenteral iron therapy are relatively infrequent in Switzerland despite the required documentation of haemoglobin prior to therapy.