 Pressure was put on local GPs to refer patients to the centres, rather than to NHS hospitals, because the primary care trusts had to pay for activity whether or not it was used.According to the NHS Partners Network, which represents private providers working within the health service, GP referral rates were rising in 2009 as patients report positive experiences back to their GPs.In 2009 a "British Medical Journal" paper concluded that up to £927m of the £1.5bn first wave of ISTC contracts "may have been paid to ISTCs for patients who did not receive treatment".