Some embodiments of the invention provide a meter and a disposable cartridge for analyzing a fluid sample confined to the disposable cartridge. The fluid sample, particularly blood, is drawn into the cartridge by capillary action, negative pressure, positive pressure, or combination thereof. The cartridge has at least one flow path, which includes at least one optical chamber for spectroscopic measurement, and at least one biosensor for biosensor measurement. The meter has a sample slot for receiving the disposable cartridge. The cartridges have electrical output contacts, and the meter slot has electrical input contacts. When the output contacts mate with the input contacts, the optical chamber becomes positioned for spectroscopic measurement. Neither biosensors nor spectroscopy can be used alone to measure key analytes in blood for effective patient care. The present invention provides joint-diagnostic spectroscopic and biosensor measurements. Optionally, plasma can be extracted from whole blood, for measuring analytes that cannot be measured accurately in whole blood. The invention provides a wider panel of blood analytes using as little as a drop of blood, at the point of patient care.