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

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

ALGAE Data Dictionary: Later life exposures, using life stage mobility assessment (algae3700-algae3742)

by Kevin Garwood

Context of Variables

These later 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.

Location of Result File

You will find these variables in a file having a name that fits the form: 
res_later_stg_mob_exp_[Date stamp].csv
which will be found in the directory: 
later_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: 
	algae37[0-16]_[pollution type]_[aggregate value]

In this pattern:

  • algae37: indicates that they refer to exposure values for later 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
algae3700_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.
algae3701_life_stage The name of a life stage. For example, "T1" may be the name of the Trimester 1 life stage.
algae3702_life_stage_duration The number of days in the life stage.
algae3703_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.
algae3704_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.
algae3705_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.
algae3706_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.
algae3707_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.
algae3708_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.
algae3709_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.
algae3710_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.
algae3711_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.
algae3712_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.
algae3713_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.
algae3714_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.
algae3715_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.
algae3716_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.
algae3717_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.
algae3718_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.
algae3719_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.
algae3720_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.
algae3721_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.
algae3722_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.
algae3723_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.
algae3724_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.
algae3725_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.
algae3726_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.
algae3727_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.
algae3728_name_sum Cumulative exposure of NAME for the given life_stage.
algae3729_name_avg Average exposure for NAME measured for the given life_stage
algae3730_name_med Median exposure for NAME measured for the given life_stage
algae3731_nox_rd_sum Cumulative exposure of NOX (road sources) for a given life_stage.
algae3732_nox_rd_avg Average exposure of NOX (road sources) for a given life_stage.
algae3733_nox_rd_med Median exposure for NOX (road sources), measured for the given life_stage
algae3734_pm10_gr_sum Cumulative exposure for PM10 (non-road sources), measured for the given life_stage
algae3735_pm10_gr_avg Average exposure for PM10 (non-road sources), measured for the given life_stage
algae3736_pm10_gr_med Median exposure for PM10 (non-road sources), measured for the given life_stage
algae3737_pm10_rd_sum Cumulative exposure for PM10 (road sources), measured for the given life_stage
algae3738_pm10_rd_avg Average exposure for PM10 (road sources), measured for the given life_stage
algae3739_pm10_rd_med Median exposure for PM10 (road sources), measured for the given life_stage
algae3740_pm10_tot_sum Cumulative exposure for PM10 (all sources), measured for the given life_stage
algae3741_pm10_tot_avg Average exposure for PM10 (all sources), measured for the given life_stage
algae3742_pm10_tot_med Median exposure for PM10 (all sources), measured for the given life_stage