Studies of oxybutynin instilled into the bladder (with or without oral oxybutynin) in children (less than 18 years) with poorly compliant neurogenic bladder, that was refractory to oral oxybutynin or who had experienced severe side effects, were eligible for inclusion in the review. Eligible study designs were randomised controlled trials (RCTs), non-randomised controlled trials, quasi-experimental studies and non-comparative case series. Case controlled studies or studies of intravesical treatment using a drug other than oxybutynin were excluded.
The primary outcome was bladder compliance. Secondary outcomes included maximum bladder capacity, detrusor pressure at maximum bladder capacity, detrusor leak point pressure, neurogenic detrusor overactivity, urinary tract infection, episodes of urinary incontinence and side effects.
In most studies, patients received 10mg oxybutynin daily (range 10 to 20mg/day or 0.1 to 0.2kg/day) instilled into the bladder with a urethral catheter. In most studies, patients used crushed pills diluted in sterile water; one study used a pharmacy prepared oxybutynin solution. Most of the included patients had a clinical diagnosis of myelomeningocele; their mean age ranged from 4.2 years to 9.5 years (range 0.3 to 18), where reported. The duration of studies ranged from three to 36 months.
Two reviewers independently selected studies for inclusion in the review.