Overactive bladder (OAB) is defined as a syndrome characterized by “urinary urgency, usually with urinary frequency and nocturia, with or without urgency urinary incontinence…”. The sine qua non for OAB is urinary urgency; if there is no urgency, one should not use the term overactive bladder. The definition of urgency, though, has been riddled with controversy, and several different subtypes have been described. 
The aim of this study is twofold: 1) to determine how well the ICD 10 code for OAB comports with the definition of OAB; i.e., how often is the term OAB misused to describe patients with symptoms not accompanied by urgency and 2) to determine what other symptoms and conditions are erroneously labelled as OAB.

This was a retrospective review of an ongoing lower urinary tract symptom (LUTS) database comprised of patients with LUTS who had an ICD 10 diagnosis of OAB and completed:
   1) a validated LUTS symptom score (LUTSS) (Validation of the Lower Urinary Tract Symptom Score, Canadian Journal of Urology 22: 5 (2015)), 
   2) 24-hour bladder diary (24H BD) 
The LUTSS and diary were completed on a mobile app*.
The accuracy of the ICD 10 OAB diagnosis was cross checked by confirming that the patient complaint of urgency was documented in the LUTSS, bladder diary and/or anamnesis (checked by EMR chart review). If the patient did not have documentation of urgency in the medical records, the ICD code was considered to be a misdiagnosis and the reasons for the misdiagnoses were tabulated. For example, a diagnosis of OAB may have been erroneously chosen for patients with painful bladder symptoms or urinary frequency without urgency.
The LUTSS is comprised of 14 questions (Q) and has 6 domains, one of which is identical to the Overactive Bladder Symptom Score. A score of ≥ 8 is considered to confirm a diagnosis of OAB, provided that urgency was documented by a score of 4 on Q3 and/or Q4 and/or a score of 3 or 4 on Q 5 and/or Q6 (see fig). Urgency was confirmed on the bladder diary if there were one or more urgency voids (grade 4 Urge Perception Score) –“I had a desperate urge...must stop what I am doing and go immediately.” Urgency was documented by anamnesis if the office note text used words compatible with urinary urgency or urge incontinence. The most granular method to document urgency is the LUTSS with multiple questions specifically asking about urgency, while the least granular method is anamnesis since urgency only needed to be mentioned.

A total of 128 patients were identified from our review of the database who completed both a 24-hour bladder diary and the LUTSS, of whom 45 had an ICD-10 diagnosis of OAB. There were 25 women and 20 men (mean age 55, SD 15). The ICD 10 code was correct in 87%. Of those patients who did not have urgency, diagnoses gleaned from chart review included such conditions as BPH, nocturia, LUTS and urethral stricture.

At first glance, the results of this study seem straightforward – in 87% of patients with an ICD diagnosis of OAB, urgency was confirmed by anamnesis, bladder diary and/or the LUTSS. Of those in whom the diagnosis was not confirmed, chart review suggested other diagnoses including BPH, nocturia, LUTS and urethral stricture.
However, when one looks at the Pearson correlation coefficient, it is striking that the higher the degree of specificity about the presence of urgency, the lower the likelihood that patients were diagnosed correctly based on the premise that in order to have overactive bladder, the patient must have urgency. This is most striking when one looks at the correlation between the ICD 10 diagnosis of OAB and the presence of urgency based on the four questions in the OABSS that deal with urgency. In that cohort, the accuracy of the ICD 10 diagnosis declined to 62%.
So, is this clinically relevant? Do patients with OAB symptoms without urgency fare as well with clinical diagnostic and treatment algorithms as those with urgency? We don't think so, but we are unaware of studies that specifically look at this. 
It was this very question that fueled the ongoing debate, which goes back some 30 years, about whether urinary urgency, as defined above, is a pathologic condition that is different from other sensations that cause people to rush to the bathroom. In 2009, we described two types of urgency – Type 1, which is an intensification of the normal urge to void (Two Types of Urgency, Neurourol and Urodynamics 28:188, (2009)) and Type 2, identical to the current definition. These types have been corroborated by others (OAB Bladder Sensations, Neurourol and Urodynamics 31:521, (2012)). 
Recently, we have identified additional sensations that can be misdiagnosed as OAB. These patients void frequently because of unpleasant sensations that they perceive in the region of bladder or urethra that cause them to void frequently in a futile attempt to relieve the symptoms. They describe those sensations as suprapubic/abdominal “pressure”, “tingling”, and an “icy hot feeling.” Whether or not these different sensations in patients with a clinical diagnosis of OAB require different diagnostic and treatment algorithms remains to be seen.

In this cohort of patients within ICD 10 diagnosis of overactive bladder, the presence of urinary urgency was documented in 87% by the overactive bladder symptom score, 24-hour bladder diary and/or and anamnesis. However, the more granular the outcome instrument was with respect to urgency, the less accurate the ICD the 10 diagnosis became. Whether or not patients with over active bladder symptoms with and without urinary urgency need different diagnostic and treatment algorithms is a question that has yet to be answered.

*Symptelligence Medical Informatics, LLC