1. An apparatus for determining one or more migraine variables associated with migraines, comprising: at least one processor; at least one memory; and at least one program module, the program module stored in the memory and configurable to be executed by the processor, the program module including: instructions for determining a statistical relationship between one or more temporal onsets corresponding to one or more events and a pattern of occurrence of a compound variable, wherein the compound variable corresponds at least to a pattern of occurrence of a first variable and a pattern of occurrence of a second variable, and wherein the determining includes contributions from presence and absence information in the pattern of occurrence of the compound variable; and instructions for identifying the first variable and the second variable as the migraine variables in accordance with the statistical relationship.