Background aim Prevention is one of the main purposes of Family Medicine leading to studies that aim to comprehend which practice is beneficial for patients and which measures can be harmful. In Portugal there is still a belief that every patient even healthy one should undergo blood tests and other examinations to perform a check-up and diagnose disorders that did not manifest and to which there were no risk factors, namely family history. This practice contributes to overdiagnosis and the related harms. The present study was designed to study the prescription pattern of ‘routine’ blood tests in Family Medicine in Portugal.

Methods We performed a cross-sectional study having as setting the Portuguese primary healthcare. A questionnaire distributed regionally by email was answered, between January and July of 2017. The physicians were surveyed on their RBTs prescription pattern and their motives for prescribing or not blood tests. The questions were based on the panel of the most prescribed analyses in the group of healthcare centres of Central Lisbon: full blood count, lipid profile, glycemia, renal function, liver function, thyroid function, prostate specific antigen (PSA). The statistical analysis was performed using the software IBM® SPSS® Statistics 23.

Results There were 323 valid answers. The mean age was 38.04 years old. Most of the inquired doctors affirmed to prescribe RBTs (51.7%) of which 74,7% are specialists. A statistically significant relation between degree and prescribing RBTs was verified (p=0.013). The majority of doctors (96.3%) refers that patients request the prescription of RBTs. The most prescribed analyses in adult age are total cholesterol (92.2%), blood glucose and triglycerides and in paediatric age blood glucose, total cholesterol and full blood count, respectively. Most of the doctors (79.4%) that prescribe RBTs do so to perform screening and the physicians that do not prescribe do so, mainly (80.8%), because it does not agree with scientific evidence.

Conclusions The results obtained reveal that most primary care doctors in Portugal still prescribe RBTs. It was also verified that most doctors have the perception that their patients often request to do a check-up. Further studies should be performed to better describe and understand the regional distribution of the prescription pattern and the evaluation of the economic impact of the prescription of unnecessary blood tests. There should be an investment in the promotion of evidence-based medicine as well as health literacy policies to adjust the practice and the expectations of patients.