Risk factor	Definition	Data extraction
Male gender		General information from EPR
Symptoms of tissue invasion	Fever, chills, malaise, flank or perineal pain, acute confusion or delirium	Laboratory codes a for patient’s temperature were used and the written lines in the EPR were electronically searched for keywords a on symptoms of tissue invasion. Also, ICPC U71 pyelonephritis, Y73 acute prostatitis and urosepsis were used
Immune disorders	Including diabetes mellitus, immunosuppressant drugs, medical history with immune disorders and malignancies in the past two years with high change of receiving chemotherapy/radiotherapy	The use of immunosuppressant/stimulant medication was based on ATC codes in EPR. Time period of usage was calculated with dosage per day and amount of prescribed medication. A list of ICPC codes a was used for immune disorders and malignancies
Renal/bladder disease	Including severe renal insufficiency (GFR<30), renal cysts, renal lithiasis, neurological bladder disorders, urinary retention, prostatism	A list of ICPC codes a was used for renal/bladder diseases, as well as the most recent GFR before the UTI
Age <12 years		General information from EPR
Pregnancy	In any trimester	A list of ICPC codes a was used. If an ICPC delivery code was present, the estimated time of pregnancy was 280 days before date of delivery. If only a pregnancy code was present, it was assumed that women presented to their GP for the first time four weeks into pregnancy
Indwelling catheter	Presence of indwelling urinary catheter	Both an electronic search of written lines in EPR for keyword ‘catheter’ was performed and the EPR prescription list was used. For each prescribed catheter on the medication list 12 weeks (maximum time period for one catheter) were added to the date of prescription, to estimate the time period of presence
Antibiotic prophylaxis	Trimethoprim 50–100 mg or nitrofurantoin 50 mg once a day as prophylaxis for UTI	ATC codes a in EPR were used. The time period during which prophylaxis was used was calculated based on the number of prescribed tablets
Failure of two ‘blindfolded’ prescribed antibiotics		It was not possible to reliably find the presence of this risk factor in EPR

(EPR=electronic patient record; ICPC code=International Classification of Primary Care code; ATC code=Anatomical Therapeutic Chemical classification code; GFR=glomerular filtration rate)

^a A full list of ICPC, ATC, laboratory codes and keywords is available from corresponding the author.