Study	Reason for exclusion
Ferenci 2010	Data were extracted about either slow responders with genotype 1 and 4 or about genotype 1 patients with partial and complete early response. Data about genotype 1 slow responders could not be isolated.
Ide 2009	Treatment duration was not 72 weeks; treatment was administered for 44 weeks after participants became negative for HCV RNA (total duration 48 to 68 weeks).
Miyase 2010	The participants had positive HCV RNA on week 8 and negative on week 12, so they could match only to our second definition of slow responders (as a subgroup of non RVR participants). However, 9/40 participants were non‐naive and had received interferon treatment earlier.
Nagaki 2009	Some of the participants that were included were non‐naive chronic HCV patients. Treatment was extended to 96 weeks.

HCV = hepatitis C virus 
 RNA = ribonucleic acid 
 SVR = sustained virological response