Researchers use a wide variety of terms and definitions in published studies on pelvic floor muscle function (PFMF), according to authors of a new study in the October issue of PTJ (Physical Therapy). They say that it's this lack of standardized terminology, combined with too much focus on how to measure versus what to measure, that may be hindering “effective communication, data gathering, and advances in the evidence-based approach to women” with urinary incontinence (UI). [Editor's note: APTA members may access the full article for free through the "sign in via society site" link on the PTJ website.]

The study examined terms related to PFMF, as well as their "conceptual" and "operational" definitions, used in 64 cross-sectional studies in women with and without UI. Authors of the study were particularly interested in how definitions of terms (or the lack of definitions) impacted both the individual studies as well as the degree to which the studies could be compared with each other.

Authors began by clarifying what they meant by "conceptual" and "operational" definitions used in the studies they reviewed. For the PTJ study's authors, a conceptual definition involves a description of what needs to be measured—for example, a conceptual definition of the term strength is capacity of a muscle to generate force. An operational definition could be a procedure, such as vaginal manometry, as well as an explanation of how it was performed.

Authors identified 196 terms used in the various studies and grouped them into 61 categories—for example, "strength" was used as an umbrella term for 11 other terms such as "pelvic floor strength." The authors then looked at how well the studies managed terms and definitions. Here's what they found:

• Only 29.7% of the studies included operational definitions of terms.
• A single study might use different terms to refer to the same muscle function.
• While "strength" was the most commonly researched muscle function, the term was conceptually defined in only 5 studies—in 3 different ways.
• The operational definitions of "strength" included both dynamometry and manometry; however, several different scales were used, making it impossible to compare results.

“Concepts are the building blocks for all thinking,” write authors, who warn against “operationism”—focusing on how to measure variables as opposed to “what is relevant to be measured.”

“Once the concept being measured becomes synonymous to the measurement outcomes, even small changes in method produce a new concept,” researchers say. This leads to an increasing number of terms and definitions that make it difficult to gather and analyze data or generalize results. It also restricts a study’s results to its “particular methodology,” authors write.

The study results, say authors, “pose an urgent need to build and adopt a standardized terminology based on a sound theoretical framework encompassing the different disciplines, related areas, researchers and policy makers in order to increase understand¬ing of PFMF in women with UI and hopefully to provide higher quality of health care.”