20.1.10. Rule Filter (Advanced Scoping)

The Rule Filter field on the Challenge Detail (Editor) editor lets you narrow which observations count toward a challenge beyond what scope and HCP type filter already do. It is optional – leave it blank and all observations in scope are counted.

20.1.10.1. Why use it

Scopes answer who; the rule filter answers what counts. Examples of the kinds of question it can answer that scope alone cannot:

• “Before-Patient and After-Patient only – ignore aseptic/body-fluid/surroundings moments.”

• “RNs and LPNs only for this challenge, everyone else for the next one.”

• “Pre-procedure moments only.”

20.1.10.2. Syntax

The field stores a small key=value expression. Two formats are accepted interchangeably:

Simple form (recommended):

key1=value1;key2=value2

JSON form:

{"key1":"value1","key2":"value2"}

Both parsers are lenient. Whitespace is trimmed. Unknown keys are ignored silently.

20.1.10.3. Supported keys

Key	Value	Effect
moments	Comma list of integers 1-5	Restricts observations to the named hand-hygiene moments. 1 = before patient, 2 = after patient, 3 = before aseptic, 4 = after body fluid, 5 = after touching patient surroundings.
hcptypes	Comma list of integer HCP type IDs	Restricts observations to the listed HCP types. Ignored when the challenge’s scope is already HCP Type (would be redundant).

20.1.10.4. Examples

“Before-patient and after-patient only”:

moments=1,2

“RN (5) and LPN (6) only”:

hcptypes=5,6

“Pre-procedure moments, RNs only”:

moments=1,3;hcptypes=5

Same as JSON:

{"moments":"1,3","hcptypes":"5"}

20.1.10.5. How it’s applied

The filter is combined into the observation WHERE clause at every computation:

• moments becomes AND (d.befpat=1 OR d.aftpat=1 OR ...) across the selected flags.

• hcptypes becomes AND d.hcptype IN (5,6).

Because the filter is applied during Compute it affects every metric equally – the observation count, compliance %, improvement delta baseline, and streak all narrow to the filtered window.

20.1.10.6. Safety

All inputs are sanitised to integers server-side before being inlined into SQL. Any non-numeric token in the comma list is silently dropped, so stray quotes, brackets, or semicolons in the rule field cannot cause SQL injection. The worst that can happen is a rule that matches fewer observations than intended.

20.1.10.7. Limitations

This is a minimal rule engine. It deliberately does not support:

• Boolean combinations beyond the implicit AND between keys.

• Arithmetic (e.g. “at least 2 of the 5 moments”).

• Free-form SQL.

If you need richer logic, create multiple challenges with different rules and compare the leaderboards. Richer operators are a future enhancement.