Within the context of the definition of OAB, the word “urgency” also needs to be defined. The current definition is the “Sudden, compelling desire to pass urine that is difficult to defer.”3
This was formally accepted by the ICS in 2002, replacing the previous definition: “Strong desire to void accompanied by fear of leakage or pain.”
One of the ongoing criticisms of the current definition is the inclusion of the word “sudden.” Some have argued that urgency may be the end result of a gradual build-up of sensation rather than always having a sudden onset.5
The reality may be that urgency can be either of these: it may be truly episodic with no prior urge to void, or it may occur as the final sensation following a gradual buildup of the urge to void. In this latter scenario, it is important to recognize that there may be a point where normal, physiologic urge changes to pathologic urgency.
Potential problems with the current definitions
One potential problem with the current definition of OAB is that, by the inclusion of the word urgency, certain conditions are eliminated that might be more usefully included, such as detrusor overactivity causing incontinence but without sensation (what used to be termed “reflex incontinence”). This can also occur in the elderly with or without obvious neurologic disease. This condition would be treated in much the same way as OAB, but due to the current definition, would not qualify for OAB diagnosis.
Similarly, the inclusion of the “in the absence of an underlying metabolic or pathologic condition” clause eliminates any symptoms secondary to urinary tract infection, cancer, stone, injury/surgery, adjacent inflammation and benign prostatic obstruction. Again, even though treatment of these symptoms may be similar to those for OAB as it is defined, the definition excludes patients with these underlying conditions from being diagnosed with OAB.
Furthermore, one of the inherent problems with the term urgency is that the symptoms are so subjective, it is difficult to assess objectively. The ICS definition of urgency can, therefore, be unclear when used in clinical trials and needs to be translated into an unequivocal form that the patient can understand.6
shows some wording that may be used to describe urgency to patients.
Communicating the concept of urgency to patients