1. Following prostatic biopsy, a 65 year old man, with spinal pain, has been confirmed as suffering from prostatic carcinoma. You are asked to prescribe him Goserelin, every 12 weeks and Cyproterone for three weeks. He asks you the reasons for having this combined therapy. The addition of the anti-androgen reduces the risk of which one of the following side effects of the gonadorelin analogue?

a ) Injection-site reaction
b ) Tumour ’flare’
c ) Hair loss
d ) Mood change
e ) Peripheral oedema

Answer: B

During the initial stage (1-2 weeks) of using Goserelin, increased production of testosterone may be associated with progression of prostate cancer. In susceptible patients, this tumour ‘flare’ may cause spinal cord compression, ureteric obstruction or increased bone pain. To reduce this risk, anti-androgen treatment (eg. Cyproterone) should be started three days before the Goserelin and continued for three weeks. The other recognised side-effects quoted will not be affected by this short term use of the anti- androgen.

2. In the process of critically appraising a randomised controlled trial (RCT), which one of the following terms is used to describe the generalisability of the trial results to your own defined patient population?

a ) Heterogeneity
b ) Reproducibility
c ) Significance
d ) External validity
e ) Positive predictive value

Answer: D

In assessments of the validity of studies of healthcare interventions, selection bias refers to systematic differences between comparison groups in prognosis or responsiveness to treatment. Random allocation with adequate concealment of allocation protects against selection bias. Other means of selecting who receives the intervention of interest, particularly leaving it up to the providers and recipients of care, are more prone to bias because decisions about care can be related to prognosis and responsiveness to treatment.
Selection bias is sometimes used to describe a systematic error in reviews due to how studies are selected for inclusion. Publication bias is an example of this type of selection bias.
Selection bias, confusingly, is also sometimes used to describe a systematic difference in characteristics between those who are selected for study and those who are not. This affects the generalisability (external validity) of a study but not its (internal) validity.

3. Your new registrar is keen to utilise her Information Management & Technology skills to enhance the care of her patients. Which one of the following is an online clinical decision support system specifically for general practitioners?

a ) MEDLINE
b ) PRODIGY
c ) NeLH
d ) OMNI
e ) EMIS
f ) VISION

Answer: B

PRODIGY is an online clinical decision support system for general practitioners. MEDLINE and OMNI are medical web-based information systems. NeLH provides access to the best current knowledge available for improving healthcare, clinical practice and patient choice. EMIS and VAMP VISION are practice based computer systems.