Does antibiotic treatment following drainage of a primary peri anal abscess prevent development of anal fistula?
We hypothesize that treatment with adjuvant antibiotics following peri anal abscess drainage will diminish development of perianal fistula.
Double-blind, placebo-controlled, randomized multicenter trial with cost-utility analysis comparing surgical drainage of perianal abscess followed by treatment with antibiotics versus surgical drainage followed by placebo drugs.
Patients =18 years old requiring drainage of a primary perianal abscess are invited to participate in the trial.
Patients with a primary perianal abscess are asked informed consent for inclusion in the trial and are randomized for treatment with antibiotics or placebo after surgical drainage of the abscess.
Standard care of a perianal abscess is drainage without postoperative antibiotics.
primary outcome is development of a perianal fistula.
Secondary outcomes are: quality of life at 12 months measured with the EQ-5D-5L with Dutch rating, resumption of work, complications
To demonstrate a reduction of perianal fistula from 30% to 15% when treated by adjuvant antibiotics with a two-sided alpha of 5% and a power of 80%, a total of 134 patients in each group is required. Taking a 10% lost to follow up percentage into account, a total of 298 patients is necessary to be included
COST EFFECTIVENESS ANALYSIS (CEA)
Cost-effectiveness and cost-utility analyses will be performed from a societal perspective comparing the of adjuvant antibiotic treatment with standard care following surgical drainage of perianal abscess.
BUDGET IMPACT ANALYSIS (BIA)
To evaluate the economic impact of adjuvant antibiotics after surgical drainage of the perianal abscess we will extrapolate the results of the economic evaluation to a nationwide level.