ALGAE Data Dictionary: Early life exposures, using life stage mobility assessment

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

ALGAE Data Dictionary: Early life exposures, using life stage mobility assessment (algae3300-algae3342)

by Kevin Garwood

Context of Variables

These early life exposure values are based on the life stage mobility assessment method. The assessment uses the location study members occupied on the first day of each life stage to represent their location for all of that life stage. It ignores exposure contributions for all other locations study members may have used during their exposure period. For each study member, cumulative, average and median exposures are assessed based on two factors:

For each life stage, the protocol counts the number of days which can be described by the following categories for data quality:

Please see the Assess the Data Quality of Each Daily Exposure Value section of the ALGAE methodology to learn more about these data quality categories.

Variables marked _err aggregate daily exposure errors for a given pollutant and life stage.

Cumulative, average and median exposures are calculated for each pollutant (NAME, NOX_rd, PM10_rd, PM10_gr, PM10_tot) for each life stage (T1, T2, T3, EL) for each person.

Location of Result File

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

Example Result File

See here.

Variable Naming Conventions

It may be quicker to understand the variables through naming conventions rather than looking at specific table entries. The basic format of variables in this section follows this pattern: 
	algae33[0-16]_[pollution type]_[aggregate value]

In this pattern:

  • algae33: indicates that they refer to exposure values for early life that are based only on the locations that study members occupied on the first day of each life stage.
  • pollution_type: will be name, nox_rd, pm10_tot, pm10_rd, pm10_gr
  • aggregate value: sum for cumulative value, avg for average value and med for median value.

The pollutant codes have the following meanings:

  • name: high level pollution that comes from outside the exposure area
  • nox_rd: Nitrogen oxide pollution coming from roads
  • pm10_rd: PM10 particulate matter coming from roads.
  • pm10_gr: PM10 particulate matter coming from sources other than roads.
  • pm10_tot: PM10 particulate matter coming from either roads or other sources.

Variable Dictionary

Variable Description
algae3300_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.
algae3301_life_stage The name of a life stage. For example, "T1" may be the name of the Trimester 1 life stage.
algae3302_life_stage_duration The number of days in the life stage.
algae3303_name_inv_addr_days The number of NAME exposure days in the life stage that the study member spent at an invalid address. See definition of Invalid address days.
algae3304_name_oob_days The number of NAME exposure days in the life stage that the study member spent living at a location that is considered outside the bounds of the exposure area. See definition of Out of bounds days.
algae3305_name_poor_addr_days The number of NAME exposure days in the life stage that the study member spent living at a location whose geocode was derived from a poor quality residential address. The geocode was used to generate exposure values, but it is still considered to be invalid because it is of such poor quality. See definition of Poor address days.
algae3306_name_missing_exp_days The number of NAME exposure days in the life stage that the study member spent living at a valid geocode which has some exposure values but not for specific days. See definition of Missing exposure days.
algae3307_name_good_addr_days The number of NAME exposure days in the life stage that the study member spent living at a geocode that is considered a good match: it has a valid geocode and it has a non-blank exposure value for a given day. See definition of Good address days.
algae3308_nox_rd_inv_addr_days The number of NOX RD exposure days in the life stage that the study member spent at an invalid address. See definition of Invalid address days.
algae3309_nox_rd_oob_days The number of NOX RD exposure days in the life stage that the study member spent living at a location that is considered outside the bounds of the exposure area. See definition of Out of bounds days.
algae3310_nox_rd_poor_addr_days The number of NOX RD exposure days in the life stage that the study member spent living at a location whose geocode was derived from a poor quality residential address. The geocode was used to generate exposure values, but it is still considered to be invalid because it is of such poor quality. See definition of Poor address days.
algae3311_nox_rd_missing_exp_days The number of NOX RD exposure days in the life stage that the study member spent living at a valid geocode which has some exposure values but not for specific days. See definition of Missing exposure days.
algae3312_nox_rd_good_addr_days The number of NOX RD exposure days in the life stage that the study member spent living at a geocode that is considered a good match: it has a valid geocode and it has a non-blank exposure value for a given day. See definition of Good address days.
algae3313_pm10_rd_inv_addr_days The number of PM10 RD exposure days in the life stage that the study member spent at an invalid address. See definition of Invalid address days.
algae3314_pm10_rd_oob_days The number of PM10 RD exposure days in the life stage that the study member spent living at a location that is considered outside the bounds of the exposure area. See definition of Out of bounds days.
algae3315_pm10_rd_poor_addr_days The number of PM10 RD exposure days in the life stage that the study member spent living at a location whose geocode was derived from a poor quality residential address. The geocode was used to generate exposure values, but it is still considered to be invalid because it is of such poor quality. See definition of Poor address days.
algae3316_pm10_rd_missing_exp_days The number of PM10 RD exposure days in the life stage that the study member spent living at a valid geocode which has some exposure values but not for specific days. See definition of Missing exposure days.
algae3317_pm10_rd_good_addr_days The number of PM10 RD exposure days in the life stage that the study member spent living at a geocode that is considered a good match: it has a valid geocode and it has a non-blank exposure value for a given day. See definition of Good address days.
algae3318_pm10_gr_inv_addr_days The number of PM10 GR exposure days in the life stage that the study member spent at an invalid address. See definition of Invalid address days.
algae3319_pm10_gr_oob_days The number of PM10 GR exposure days in the life stage that the study member spent living at a location that is considered outside the bounds of the exposure area. See definition of Out of bounds days.
algae3320_pm10_gr_poor_addr_days The number of PM10 GR exposure days in the life stage that the study member spent living at a location whose geocode was derived from a poor quality residential address. The geocode was used to generate exposure values, but it is still considered to be invalid because it is of such poor quality. See definition of Poor address days.
algae3321_pm10_gr_missing_exp_days The number of PM10 GR exposure days in the life stage that the study member spent living at a valid geocode which has some exposure values but not for specific days. See definition of Missing exposure days.
algae3322_pm10_gr_good_addr_days The number of PM10 GR exposure days in the life stage that the study member spent living at a geocode that is considered a good match: it has a valid geocode and it has a non-blank exposure value for a given day. See definition of Good address days.
algae3323_pm10_tot_inv_addr_days The number of PM10 TOT exposure days in the life stage that the study member spent at an invalid address. See definition of Invalid address days.
algae3324_pm10_tot_oob_days The number of PM10 TOT exposure days in the life stage that the study member spent living at a location that is considered outside the bounds of the exposure area. See definition of Out of bounds days.
algae3325_pm10_tot_poor_addr_days The number of PM10 TOT exposure days in the life stage that the study member spent living at a location whose geocode was derived from a poor quality residential address. The geocode was used to generate exposure values, but it is still considered to be invalid because it is of such poor quality. See definition of Poor address days.
algae3326_pm10_tot_missing_exp_days The number of PM10 TOT exposure days in the life stage that the study member spent living at a valid geocode which has some exposure values but not for specific days. See definition of Missing exposure days.
algae3327_pm10_tot_good_addr_days The number of PM10 TOT exposure days in the life stage that the study member spent living at a geocode that is considered a good match: it has a valid geocode and it has a non-blank exposure value for a given day. See definition of Good address days.
algae3328_name_sum Cumulative exposure of NAME for the given life_stage.
algae3329_name_avg Average exposure for NAME measured for the given life_stage
algae3330_name_med Median exposure for NAME measured for the given life_stage
algae3331_nox_rd_sum Cumulative exposure of NOX (road sources) for a given life_stage.
algae3332_nox_rd_avg Average exposure of NOX (road sources) for a given life_stage.
algae3333_nox_rd_med Median exposure for NOX (road sources), measured for the given life_stage
algae3334_pm10_gr_sum Cumulative exposure for PM10 (non-road sources), measured for the given life_stage
algae3335_pm10_gr_avg Average exposure for PM10 (non-road sources), measured for the given life_stage
algae3336_pm10_gr_med Median exposure for PM10 (non-road sources), measured for the given life_stage
algae3337_pm10_rd_sum Cumulative exposure for PM10 (road sources), measured for the given life_stage
algae3338_pm10_rd_avg Average exposure for PM10 (road sources), measured for the given life_stage
algae3339_pm10_rd_med Median exposure for PM10 (road sources), measured for the given life_stage
algae3340_pm10_tot_sum Cumulative exposure for PM10 (all sources), measured for the given life_stage
algae3341_pm10_tot_avg Average exposure for PM10 (all sources), measured for the given life_stage
algae3342_pm10_tot_med Median exposure for PM10 (all sources), measured for the given life_stage