ALGAE Data Dictionary: Later life stage data (algae1200-algae1206)

An automated protocol for assigning early life exposures to longitudinal cohort studies

ALGAE Data Dictionary: Later life stage data (algae1200-algae1206)

by Kevin Garwood

Context of Variables

These variables describe the name and temporal boundaries of life stages that are used in the later life analysis. Note that in the default version of ALGAE, the software will alter life stage boundaries for some premature births. If you see that the start date and end date of T3 are both null, you can assume that the study member was born as a very premature baby. Please see Calculations and Algorithms to learn more about how ALGAE corrects for these cases.

Note that some of these variables may be considered too sensitive to take off-site. Check your information governance policies and see: Assessing Sensitive Data in the Data Dictionary.

Location of Result File

You will find these variables in a file having a name that fits the form: 
res_later_life_stages_[Date stamp].csv
which will be found in the directory: 
later_life/results/life_stage_data

Example Result File

See here.

Variable Naming Conventions

The basic format of variables in this section follows this pattern: 
	algae12[00-05]_[pollution type]_[aggregate value]

In this pattern, algae12 indicates that they describe properties of life stages used in the later life analysis.

Variable Dictionary

Variable Description
algae1200_person_id An anonymised or pseudonymised identifier which represents a study member. ALGAE uses this variable to link data together for a given study member.
algae1201_ith_life_stage Indicates the order of life stages. For example, suppose the life stages T1, T2, T3 and EL. The temporal ordering of the stages would be 1 for T1, 2 for T2, 3 for T3 and 4 for EL.
algae1202_life_stage The name of the life stage. For example, EL stands for the later life period.
algae1203_life_stage_year The calendar year of the first day of the life stage. For example, if the EL period runs from 18-11-1996 to 17-11-1997, the life stage year will be 1996.
algae1204_start_date The start date of the life stage.
algae1205_end_date The end date of the life stage.
algae1206_life_stage_duration The total number of days in the life stage, including both the start and end days.