diff --git a/mimic-iv/concepts/README.md b/mimic-iv/concepts/README.md
index c075a2bb..b2c3bd48 100644
--- a/mimic-iv/concepts/README.md
+++ b/mimic-iv/concepts/README.md
@@ -1,77 +1,89 @@
 # MIMIC-IV Concepts
 
+This folder contains scripts to generate useful abstractions of raw MIMIC-IV data ("concepts").
+The scripts are written using the **BigQuery Standard SQL Dialect**. Concepts are categorized into folders if possible, otherwise they remain in the top-level directory. The [postgres](/mimic-iv/concepts_postgres) subfolder contains automatically generated PostgreSQL versions of these scripts; [see below for how these were generated](#postgresql-concepts). Concepts are categorized into folders if possible, otherwise they remain in the top-level directory.
+
+The concepts are organized into individual SQL scripts, with each script generating a table. The BigQuery `mimiciv_derived` dataset under `physionet-data` contains the concepts pregenerated. Access to this dataset is available to MIMIC-IV approved users: see the [cloud instructions](https://mimic.mit.edu/docs/gettingstarted/cloud/) on how to access MIMIC-IV on BigQuery (which includes the derived concepts).
+
+See the [top-level readme](mimic-iv/README.md) for more information about generating the concepts.
+
+## Concept Index
+
 Concepts in this folder:
 
+```
 ├── comorbidity
-│   └── charlson.sql
+│   └── charlson.sql
 ├── demographics
-│   ├── age.sql
-│   ├── icustay_detail.sql
-│   ├── icustay_hourly.sql
-│   ├── icustay_times.sql
-│   └── weight_durations.sql
+│   ├── age.sql
+│   ├── icustay_detail.sql
+│   ├── icustay_hourly.sql
+│   ├── icustay_times.sql
+│   └── weight_durations.sql
 ├── firstday
-│   ├── first_day_bg.sql
-│   ├── first_day_bg_art.sql
-│   ├── first_day_gcs.sql
-│   ├── first_day_height.sql
-│   ├── first_day_lab.sql
-│   ├── first_day_rrt.sql
-│   ├── first_day_sofa.sql
-│   ├── first_day_urine_output.sql
-│   ├── first_day_vitalsign.sql
-│   └── first_day_weight.sql
+│   ├── first_day_bg.sql
+│   ├── first_day_bg_art.sql
+│   ├── first_day_gcs.sql
+│   ├── first_day_height.sql
+│   ├── first_day_lab.sql
+│   ├── first_day_rrt.sql
+│   ├── first_day_sofa.sql
+│   ├── first_day_urine_output.sql
+│   ├── first_day_vitalsign.sql
+│   └── first_day_weight.sql
 ├── measurement
-│   ├── bg.sql
-│   ├── blood_differential.sql
-│   ├── cardiac_marker.sql
-│   ├── chemistry.sql
-│   ├── coagulation.sql
-│   ├── complete_blood_count.sql
-│   ├── creatinine_baseline.sql
-│   ├── enzyme.sql
-│   ├── gcs.sql
-│   ├── height.sql
-│   ├── icp.sql
-│   ├── inflammation.sql
-│   ├── oxygen_delivery.sql
-│   ├── rhythm.sql
-│   ├── urine_output.sql
-│   ├── urine_output_rate.sql
-│   ├── ventilator_setting.sql
-│   └── vitalsign.sql
+│   ├── bg.sql
+│   ├── blood_differential.sql
+│   ├── cardiac_marker.sql
+│   ├── chemistry.sql
+│   ├── coagulation.sql
+│   ├── complete_blood_count.sql
+│   ├── creatinine_baseline.sql
+│   ├── enzyme.sql
+│   ├── gcs.sql
+│   ├── height.sql
+│   ├── icp.sql
+│   ├── inflammation.sql
+│   ├── oxygen_delivery.sql
+│   ├── rhythm.sql
+│   ├── urine_output.sql
+│   ├── urine_output_rate.sql
+│   ├── ventilator_setting.sql
+│   └── vitalsign.sql
 ├── medication
-│   ├── acei.sql
-│   ├── antibiotic.sql
-│   ├── dobutamine.sql
-│   ├── dopamine.sql
-│   ├── epinephrine.sql
-│   ├── milrinone.sql
-│   ├── neuroblock.sql
-│   ├── norepinephrine.sql
-│   ├── norepinephrine_equivalent_dose.sql
-│   ├── nsaid.sql
-│   ├── phenylephrine.sql
-│   ├── vasoactive_agent.sql
-│   └── vasopressin.sql
+│   ├── acei.sql
+│   ├── antibiotic.sql
+│   ├── arb.sql
+│   ├── dobutamine.sql
+│   ├── dopamine.sql
+│   ├── epinephrine.sql
+│   ├── milrinone.sql
+│   ├── neuroblock.sql
+│   ├── norepinephrine.sql
+│   ├── norepinephrine_equivalent_dose.sql
+│   ├── nsaid.sql
+│   ├── phenylephrine.sql
+│   ├── vasoactive_agent.sql
+│   └── vasopressin.sql
 ├── organfailure
-│   ├── kdigo_creatinine.sql
-│   ├── kdigo_stages.sql
-│   ├── kdigo_uo.sql
-│   └── meld.sql
+│   ├── kdigo_creatinine.sql
+│   ├── kdigo_stages.sql
+│   ├── kdigo_uo.sql
+│   └── meld.sql
 ├── score
-│   ├── apsiii.sql
-│   ├── lods.sql
-│   ├── oasis.sql
-│   ├── sapsii.sql
-│   ├── sirs.sql
-│   └── sofa.sql
+│   ├── apsiii.sql
+│   ├── lods.sql
+│   ├── oasis.sql
+│   ├── sapsii.sql
+│   ├── sirs.sql
+│   └── sofa.sql
 ├── sepsis
-│   ├── sepsis3.sql
-│   └── suspicion_of_infection.sql
+│   ├── sepsis3.sql
+│   └── suspicion_of_infection.sql
 └── treatment
     ├── code_status.sql
     ├── crrt.sql
     ├── invasive_line.sql
     ├── rrt.sql
-    └── ventilation.sql
\ No newline at end of file
+    └── ventilation.sql
+```