Progress and Research
Research Sample Completion Calculator
Track progress toward a usable research sample after excluding incomplete or ineligible collected cases.
Enter the sample counts
Usable sample progress
Collecting 420 cases and excluding 38 leaves 382 usable cases, or 76.4% of a 500-case target. At 24 usable cases per day, the remaining 118 cases require about five recruitment days.
Calculation basis
Assumption: The days estimate assumes the entered pace is already net of exclusions and remains stable; it is not a statistical power calculation.
Collected is not the same as analyzable
Consent failures, duplicate records, eligibility failures, missing primary outcomes, or quality checks can reduce the usable sample. Report collected and excluded counts rather than quietly replacing one with the other.
Exclusion rules should be established before examining outcomes whenever the study design permits. Changing them to reach a preferred result undermines the record.
A companion calculation can analyze recruitment dispositions and survey completions.
Keep recruitment and analysis counts separate
Maintain a flow record from approached or invited cases through consent, eligibility, collection, exclusion, and final analysis. The usable count in this calculator belongs to one stage of that flow. Later exclusions or analysis-specific missingness may produce another denominator that should be named rather than silently replacing the recruitment total.
Compare the forecast with site capacity, recruitment windows, quotas, and the remaining budget. A stable recent pace can still be impossible to maintain when one site closes or a subgroup quota fills. Record each forecast date and its assumed net rate so changes in the expected finish can be explained.
Oversampling and subgroup targets
A study may intentionally recruit beyond the minimum to protect against later exclusions or to fill subgroup quotas. In that case, enter the operational recruitment target rather than the bare minimum and document why it is larger. Track subgroup completion separately when one overall percentage could conceal a shortfall in a required stratum.
Once recruitment closes, replace the forecast with a final flow count. The resulting analyzable sample may differ again across outcomes because missing data and analysis criteria are not always identical.
Recruitment pace can move
Seasonality, reminder waves, site activation, participant fatigue, and quota restrictions can alter net daily recruitment. Update the pace from a recent window that represents the current phase.
Reaching a numeric target does not establish representativeness or sufficient power for every analysis. Those questions require the sampling plan and statistical design.
The work can also use a curriculum-focused progress measure.
Questions that affect interpretation
Why subtract exclusions before calculating progress?
The target is defined as usable cases, so known unusable records cannot satisfy it.
Can completion exceed 100%?
Yes, when recruitment continues beyond the target. Report the final usable sample separately.
Is the estimated finish date guaranteed?
No. The calculation assumes a stable net recruitment pace.
Does this calculate statistical power?
No. Sample-size justification and power analysis require a statistical model.
Forecast from net usable cases
- State the target as usable cases.
- Apply documented exclusion criteria.
- Calculate net usable progress.
- Estimate pace from recent usable additions.
- Reforecast when recruitment conditions change.