Minimum Measurements for Epidemiologic Analyses
The minimum set of measurements that are required to make a clinic-based experience epidemiologically understood are easily accessible in health facilities as shown in Table 1. Patient identifiers, date of ART initiation and dates of all visits are enough to enumerate the cohort, estimate ART access and identify patients lost-to-follow-up. Addition of common measurements such as socio-demographic characteristics (age, sex, baseline WHO stage, etc.), clinic structures (availability of TB diagnostics, distance from home to clinic, etc.) can provide cross-sectional understanding of the clinic population. Most of these factors are time-invariant, and retrievable because they were routinely measured and recorded at the health facilities in the course of clinical care.
1: Minimum Measurements Required for Epidemiologic Analyses
|
Priority |
Measurements |
Parameters that Can be Estimated |
|
Tier 1: Enumerates the cohort and estimates elementary descriptive statistics
|
Patient Identifier ART initiation date Visit dates |
Time zero characteristics of a cohort Number of patients accessing care Number of patients starting ART Number of patients LTFU |
|
Tier 2: Cross-sectional characteristics of patients |
Patient Age Patient Sex Patient Height and Weight Pre-ART CD4-T-cell count (if applicable) Pre-ART WHO stage classification Enrollment date into HIV Care and Treatment Program ART initiation date (if applicable) All clinic visits dates |
Description of patient characteristics at time of engagement in care Factors associated with clinical presentation Associations between clinical characteristics at time of presentation |
|
Tier 3: Characterise and describe structural level predictors |
Stock out dates Availability of CD4 or viral load testing |
Description of program characteristics |
|
Tier 4: Sampling-based Outcomes |
Survival & retention in care ART initiation among those not on ART |
Presence of outcomes obtained through sampling can initiate epidemiologic analyses to identify the causes of mortality and retention in care |