EURURO Vol. 72 No. 3

Introduction

Underactive bladder (UAB), which is considered to be the

symptom complex of urodynamically diagnosed detrusor

underactivity (DU), is a condition that is relatively under-

researched. The current working definition describes UAB as

‘‘characterised by prolonged urination time with or without

sensation of incomplete bladder emptying, usually with

hesitancy, reduced sensation on filling, and a slow stream’’

[1]

In men and women presenting with lower urinary tract

symptoms (LUTS) and referred to urodynamic studies, the

prevalence of DU has been shown to be up to 40% in men

and 13% in women

[2]

and as much as 48% in particular

groups such as male patients over 70 yr of age

[3] .

In men,

DU has been reported alongside coexisting bladder outlet

obstruction or detrusor overactivity (DO) in 47% of subjects,

and with coexisting DO or urodynamic stress urinary

incontinence in 73% of female patients

[2]

. It is recognised

that there is an overlap of LUTS associated with these

conditions and UAB, such as slow flow, nocturia, increased

urinary frequency, and incontinence

[1,4,5]

. The symptom-

atic burden of LUTS associated with DU

[5–7]

and known

impact of LUTS on quality of life

[8,9]

highlight the

requirement to understand how patients with UAB feel

and function for clinical outcome assessment purposes.

Currently, no fully validated patient reported outcome

(PRO) measures exist for the assessment of UAB. In order for

a PRO instrument to be used in patient management,

exploration of the reported symptoms, signs, or other

functional aspects should be carried out in a sample of

patients known to have the condition, using accepted

qualitative methodology. In this type of study an exact

representative sample is not required, but a good spread of

participant characteristics is advantageous in order to

capture all relevant backgrounds and experiences of the

condition

[10]

. There is no definitive sample size for a study

such as this but 30 or 40 interviews are typical

[9,11,12]

. To

our knowledge, this is the first qualitative research study

which focuses on elucidating the patient reported experi-

ence of UAB. This study also aims to contribute essential

evidence of content validity for a new PRO measure

[13,14]

for the assessment of the symptoms, signs, and impact of

UAB in research and clinical practice.

Materials and methods

Qualitative methods were employed in order to understand the

experience of UAB from a patient perspective. Semistructured interviews

were conducted with a purposive sample of male and female patients

with a primary diagnosis of DU. Patients with DU alone and in

combination with other common coexisting urological conditions, were

interviewed to ensure the relevance of the PRO instrument to all patients

with the condition. The primary objective to the interviews was to elicit

the symptoms, signs, and impact of UAB, with an emphasis on capturing

key idiomatic expressions and language used to describe their symptoms.

Interviews were conducted by trained qualitative researchers either

in-person at the patient’s home, in situ at the hospital, or over the phone.

Informed written consent was obtained to participate and audio record

the interviews, which were then transcribed verbatim and organised

using qualitative research software package NVivo v10 (QSR Interna-

tional, Victoria, Australia). Following the first exploratory interviews, an

inductive approach

[15]

[6_TD$DIFF]

analysis of the transcripts revealed concepts

that contributed to the ongoing development of a coding framework.

Concepts identified early on in the coding process were followed-up in

subsequent interviews through iterative revisions of an interview

schedule. Data collection and analysis continued concurrently, using a

reflexive and constant comparison approach

[16]

. Concepts relating to

symptom or impacts which were spontaneously reported in the

interview (without prompting by the interviewer) were given particular

attention. Towards the end of data collection, concepts were coded by

urologic defined symptoms (eg, ‘‘hesitancy,’’ ‘‘increased urinary fre-

quency,’’ ‘‘urgency’’) which categorized the data within the current

urological and theoretical context

[17,18]

. Discussion meetings between

researchers evaluated discrepant codes to achieve consensus and

consistent coding across transcripts. Interviews continued until the

dataset was considered saturated, that is, when it was considered that no

further concepts relevant to DU were likely to be found by conducting

further interviews. Ethics approval was granted as a substantial

amendment of an existing project: Reference 087/99.

2.1.

Sample inclusion criteria

Male and female patients of 18 yr of age or over with a slow stream

associated with a weak bladder contraction, were selected by retrospec-

tive review of the urodynamic reports of patients referred for pressure

flow studies (PFS).

Table 1

shows the urodynamic criteria used to select

patients with a primary diagnosis of DU. The patients were grouped by

the presence or absence of coexisting urological conditions.

Results

A total of 44 semistructured interviews were conducted in

Bristol, UK, from January 2014 to December 2014.

Table 2

summarises the demographic and clinical characteristics of

the sample. All patients were Caucasian, and came from a

variety of educational backgrounds (ranging from school

leaver at 16 yr or younger, to college or university educated)

and occupations (manual, service, and professional).

Table 1 – Diagnosis group inclusion criteria and number of patients per diagnosis group

All DU patients included in the study (

= 44)

Males:

BCI

100

Females:

det

max

20 cmH

BOOI

max

15 ml/s

DU without coexisting urological conditions (

= 19)

DU + coexisting urological conditions (

= 25)

Mild SUI/USI (

= 7)

Mild DO (

= 8)

BOO-E (

= 5)

BOOI 20 to

BOO (

= 5)

BOOI 40

BCI = bladder contractility index

[3_TD$DIFF]

; BOO = Bladder Outlet Obstruction; BOO-E = Bladder Outlet Obstruction in the Equivocal Range; BOOI = Bladder Outlet

Obstruction Index

[4_TD$DIFF]

; DO = Detrusor overactivity; P

det

max

= detrusor pressure at maximum flow; Q

max

= maximum flow rate

[5_TD$DIFF]

; SUI = Stress Urinary Incontinence;

USI = Urodynamic Stress Incontinence.

E U R O P E A N U R O L O G Y 7 2 ( 2 0 1 7 ) 4 0 2 – 4 0 7

403