Making ms_extractlabs easier to maintain

DEV-41601 · Code changes and rationale

Move repeated work into helpers. Make inputs explicit. Keep the distinct extraction rules visible.

inputfiles/macros/ms_extractlabs.sas

DEV-41601 · ms_extractlabs.sas

Make dependencies visible

Three values now enter through parameters with empty defaults:

  • labcodsmap: the lab code map dataset in INFOLDER.
  • patidlen: the storage length of PatID.
  • labpxlen: the character length of the procedure code, PX.

This removes three implicit dependencies on macro variables outside the macro.

LABTABLE and NUMPARTITIONS remain global inputs by design. The header now documents that boundary.

DEV-41601 · ms_extractlabs.sas

Give each helper one job

The file now defines the main macro and four top-level helpers.

  • getlabres(labresult=) checks numeric or character result criteria.
  • createseqadate(labdatetype=) selects Adate from the configured date priority.
  • ms_lab_filterresults(...) combines result checks, date selection, and optional care-setting checks.
  • ms_lab_writeorappend(...) writes results and removes specified temporary datasets.

The first two replace nested definitions. The other two replace repeated blocks.

Keep the helpers in the same file, with explicit parameters.

DEV-41601 · ms_extractlabs.sas

Share repeated steps, not distinct joins

Each extraction path now uses the same filter and output helpers.

Keep the matching logic separate:

  • LAB01: match the mapped combination of laboratory attributes.
  • LAB02: match the LOINC code.
  • Other code types: match the procedure code and its code type.

The shared filter keeps one deliberate difference: ptlocfilter=N for LAB01 and Y for the other paths.

Why: these joins express different rules. Combining them would hide those differences.

DEV-41601 · ms_extractlabs.sas

Use output data instead of a flag

Previously, newrun tracked whether an earlier extraction had written rows.

The new helper checks OUTFILE directly with %isdata:

OUTFILE has rows  →  append the next extraction
OUTFILE is empty  →  replace it with the next extraction

Why: the row count already holds the information that the flag tracked.

An empty extraction leaves the next step in replace mode. Always appending would change the first result's column order and attributes.

DEV-41601 · ms_extractlabs.sas

Keep internal state local and reject missing lengths

%local message labdatetype labresult caresettingvar part;

These variables now belong to the current invocation, not an outer scope.

  • The filter helper writes missing-date warning text to the main macro's local message variable.
  • Blank patidlen or labpxlen produces an error and returns before output creation.
  • Empty LABTABLE and labcodsmap remain valid for the supported no-lab-data path.

Why: reject missing required lengths without rejecting an intentional absence of lab data.

DEV-41601 · ms_extractlabs.sas

Copy follows writing-for-a-technical-audience and ste-writing (STE-flavored). Rationale source: /home/scarndp/.local/share/polytoken/sessions-v1/0e74w5-shaft/plan-001.md. This presentation describes the refactor intent and source structure, not runtime verification.

The plan follows existing team practice: parameter defaults stay empty rather than referring to global macro variables. It retains LABTABLE and NUMPARTITIONS because they are shared configuration across the codebase.

LAB01 already matches pt_loc as part of the mapped attributes. The other paths retain their separate care-setting filter. A Y value applies that filter only when the care-setting criterion is nonblank. The main macro still removes identical rows after the extraction paths finish.

The main macro first creates an empty OUTFILE with column attributes. The old DATA-step assignment set newrun only when the step processed an observation. The helper retains PROC DATASETS APPEND FORCE for a populated output.

The entry check detects blank lengths. It does not validate numeric ranges or all possible invalid values. The header also documents the new parameters, helper macros, output handling, and isdata.sas dependency. The refactor aims to preserve supported extraction behavior while making its dependencies and shared steps easier to maintain.