Set acceptance limits

Limits go on Set up, in Acceptance limits. Calibration verification places its main settings first, followed by Additional acceptance limits; reference interval verification does the same when it has a staged rule. Enter limits before the first calculation: once a study that needs a limit has data, its main button reads Add a limit until one is added. The choices each study offers, limit types and how outcomes are decided are in Acceptance limits. Carryover, calibration verification, PT and INR, glucose meter error grids, sigma, measurement uncertainty and proficiency tracking keep their limits with their other settings on Set up (list).

1. Select Enter your own limit. With limits already saved, the same button sits below them.
2. Under What to limit, choose one statistic. Each choice shows its unit.
3. Enter the limit in that unit, for example Largest acceptable within-laboratory CV (%). Type it with a decimal point (1.5) and as a positive number for a ± limit.
   • For an allowable difference, such as bias or a specimen difference, fill in the study-unit box, the percentage box, or both. With both, choose under With both limits: Pass when within either (the larger allowance) or Pass only when within both.
   • For an SD limit, fill in Maximum SD, Maximum CV (%), or both, the same way.
4. Under Applies to, keep All levels or choose one level, analyzer or storage condition. Before any results exist, leave the field blank for all levels or conditions, or type the label exactly as it will appear in the data. An SD usually changes with concentration, so add one SD limit per level or use one CV limit for all levels.
5. If only one direction matters, expand One-sided limit and choose under Direction: Only too high: at most + the limit or Only too low: at least − the limit.
6. If a result exactly on the limit should fail, expand Equality at the limit and choose Not met (< or >).
7. For Bias at a medical decision level, choose the level under Medical decision level, or choose Add a decision level… and type a new one in the study unit. Add one limit per decision level.
8. Select Add limit, then Save changes.

To change a limit, select Edit on it, then Update limit. Remove limit deletes it.

Bias, method comparison, instrument comparison, reagent lot comparison and linearity studies offer limits from the CLIA / CAP proficiency-testing table, which is also under Library → Acceptance limits.

• If the button reads Add CLIA / CAP limit and shows the limit, for example Albumin, serum: ±8%, select it: the limit is added for the study's main check. Then select Save changes. Other CLIA / CAP limits opens the whole table.
• Otherwise:
  1. Select Use a CLIA / CAP limit, search by analyte and select Use on its row. The analyte is also recognised by its usual names and abbreviations, for example Total bilirubin, HDL, A1c or aPTT.
  2. The limit dialog opens filled in, with the table row, its source and any note at the top. Choose another analyte goes back to the table.
  3. Under What to limit, keep the first choice or pick another, such as Bias at a medical decision level with its Medical decision level.
  4. Select Add limit, then Save changes. The limit keeps the table as its source unless you change the numbers.

If your unit differs from the table's, or the row is based on a peer-group SD, a qualitative rule or a dilution rule, convert it with your assigned SD or study rule and enter it as your own limit.

1. In the limit dialog, under What to limit, select More statistics. It appears where the study calculates more than the dialog lists; for a new reference interval, Enter your own limit opens it directly.
2. Under What to check, choose the statistic.
3. Under Limit type, where offered, choose the type and fill in its values (limit types). For ±2 mg/dL as Absolute limits, enter -2 and 2.
4. Set Applies to as above, then select Add limit and Save changes.

To require a specimen within both a study-unit and a percentage part, use Enter your own limit and choose Pass only when within both.

1. Under Limit type, choose Concentration-dependent limits.
2. Enter the Assigned value or Medical decision level. A specimen rule needs neither.
3. For each range, enter the starting and ending concentrations, the Allowed difference (±) and its Unit. Leave To blank for no maximum. Select Add range for another row; Remove deletes that range.
4. List ranges in order, each starting where the one before ends. How range boundaries work gives the reminder.
5. Select Add limit, then Save changes.

1. Edit, add or remove limits.
2. Select Recalculate results on Data or Results. It saves your changes first. Until you do, the outcomes on screen come from the earlier calculation.

• To save them: below a study's limits, select Save as a reusable set and give it a name. It keeps this study's analyte, unit, matrix and instrument. Saving again under the same name makes a new version.
• To reuse them: in a study with no limits, select Reuse limits from a saved set or another study (shown when a saved set for the same analyte and unit, or another study of the same type and unit in this project, exists). Pick it under Copy the limits of, select Copy limits, then Save changes. Check the copied limits before you calculate.
• To manage saved sets: in the menu, Library → Acceptance limits lists them with Rename and Delete (a deletion is permanent and asks first), beside the CLIA / CAP table.