Complex sentence: Initially several institutions of higher education in Rhode Island formed the OSHEAN membership, but in September 2001, the consortium expanded into the health care community when Lifespan became OSHEAN's 11th member.
Split into simpler sentences: Initially several institutions of higher education in Rhode Island formed the OSHEAN membership. In September 2001 the consortium expanded into the health care community after Lifespan became OSHEAN's 11th member.