Screening: A double-edged sword

There has been much debate about the role of screening in primary care. Evidence-based screening for diseases, such as hypertension, diabetes and depression, has been found to improve health outcomes and reduce burden of disease.1 On the other hand, screening, particularly using inaccurate tests, may lead to over-investigations, over-diagnosis and over-treatment, causing more harm than good.2 Moreover, the recommendations for screening keep changing; prostate specific antigen, which has been recommended as part of routine screening in the USA for decades, is now considered as a grade D evidence according to the US Preventive Service Task Force.3

For the public, screening can be a double-edged sword. While some are keen to find out as early as possible whether they suffer from a disease so that action can be taken to cure it, others would rather let nature takes its course and believe that ‘what I don’t know won’t hurt’. In Malaysia, this is complicated by attractive but indiscriminate screening packages offered by the health industries, as well as free screening offered for commercial reasons, such as to justify the use of health supplements. Using foreign questionnaires as a screening tool in Malaysia can be problematic too because of language and cultural differences; questionnaires must be translated and validated to suit the local context before it can be used in clinical practice or for research.

In this issue of MFP, four original articles touch on screening and monitoring for common health conditions encountered in general practice i.e. overactive bladder, hypertension, and mental health problems in diabetes. Ahmad SM et al found that nearly one in five women attending a gynaecology clinic had symptoms of overactive bladder, of which more than half did not seek help because they did not feel that the urinary symptoms were a problem, felt ashamed to admit or thought that the symptoms would be temporary.4 Tan KC et al and Chew BH et al used generic (DASS) and disease-specific (Diabetes Distress Scale) questionnaires to screen for depression, anxiety, stress and distress in patients with diabetes, respectively.5,6 Both found high prevalence of depression (1 in 4) and distress (1 in 10) in patients with diabetes attending primary care clinics in both the public and private sectors.

Tong et al validated the Malay version of the Hills-Bone compliance to high blood pressure therapy scale (HBTS), which assesses patients’ compliance to medication, appointment and salt intake.7 They found the Malay version of the HBTS questionnaire to be invalid in the local primary care setting. This highlights the importance of validation; researchers and clinicians must resist the temptation to translate and use a foreign questionnaire without proper validation. This might lead to erroneous conclusions.

When making a decision whether or not to screen, besides considering the Wilson’s screening criteria,8 primary care doctors should keep abreast of the latest clinical evidence on screening, inform patients the pros and cons of screening, and guide them to make an informed decision what is best for their health.