Table 2.

Schedule of enrolment, intervention and assessments

Study period
Time point	Recruitment	Trial visits
	W24†	Active				Washout
		W0	W2	W4	W8	W12
Enrolment
Screening	X
Informed consent	X
Randomisation	X
Intervention
High water intake
Ad libitum water intake
Assessment
Medical history	X
Medication review	X	X	X	X	X	X
Physical examination	X	X	X	X	X	X
Vital signs (blood pressure, pulse rate and oximetry)	X	X	X	X	X	X
Height	X
Weight	X	X	X	X	X	X
Haematology (full blood count)	X
Biochemistry (urea, creatinine, electrolytes, serum osmolality)	X	X	X	X	X	X
Biochemistry (liver function and bone profile)	X
Measured GFR*		X	X	X
Urine SG	X	X	X	X	X	X
Spot urine osmolality	X	X	X	X	X	X
24 hours urine collection (volume and osmolality)	X		X		X	X
Home uSG monitoring‡		X	X	X	X
SPLASH monitoring		X	X	X	X
Dietary assessment	X	X		X		X
Pain questionnaire‡		X			X
Acceptability questionnaire‡		X			X
EQ5D‡		X			X

*⁵¹Cr-EDTA measured GFR performed as part of a substudy in eight participants in the HW group.

†24 weeks prestudy recruitment period.

‡Recorded using the DRINK smartphone app.

GFR, glomerular filtration rate; uSG, urine specific gravity.