It looks like there is a header/title at , numeric grouping at  “1.\tINFECTIOUS AND PARASITIC DISEASES”, subgrouping by ICD-9 code ranges, at  “Intestinal infectious diseases (001-009)” and then 3-digit ICD-9 codes followed by a specific diagnosis, at  “007\tOther protozoal intestinal diseases”. At the end we want to produce three separate data frames that we’ll categorize as:
Groups: the title which contains the general diagnosis grouping
Subgroups: the range of ICD-9 codes that contain a certain diagnosis subgroup
Classification: the specific 3-digit ICD-9 code that corresponds with a diagnosis
It’s a beefy article full of insight.