Overactive Bladder Symptoms in Female Health Profession Students: Bladder Diary Characteristics and Impact of Symptoms on Health-Related Quality of Life

Abstract

Introduction:

There is limited information on overactive bladder (OAB) symptoms, their association with bladder irritants, or the effect of OAB on health-related quality of life (HRQoL) in young women. We evaluated these issues in a group of young female health profession students.

Methods:

All female students (n = 964) attending a university in the Pacific Northwest were recruited via email or an in-person informational meeting to participate in this descriptive cross-sectional study. Outcome measures included the OAB-questionnaire, a 4-day bladder diary, and a demographic questionnaire. OAB was diagnosed if a participant reported an average of at least one episode of urgency per day on the bladder diary. Participant characteristics, bladder diary results, and HRQoL were compared using chi square, Fisher's exact test, and t-tests.

Results:

With a response rate of 21.2%, the average participant age was 25.5 years and 21.7% of participants were identified as having OAB. Participants with OAB consumed more caffeine (mean [standard deviation [SD] 2.0 [1.5] vs. 1.5 [1.2], p = 0.016), more carbonated beverages (mean [SD] 0.5 [0.6] vs. 0.3 [0.5], p = 0.047), more total units of bladder irritants (mean [SD] 3.1 [2.0] vs. 2.1 [1.6], p = 0.002), and had significantly worse HRQoL (p = 0.001) than those without OAB. No differences were found for other parameters measured.

Conclusion:

Participants with OAB consumed more bladder irritants than participants without OAB. Future research should address larger groups of young women from different backgrounds, as well as other factors or characteristics that could be associated with OAB.

Introduction

Overactive bladder (OAB), a common condition with a substantial negative impact on health-related quality of life (HRQoL), was introduced as a stand-alone diagnosis in 1997. The definition of OAB has changed with time as the understanding of the condition has improved.¹ In 2002, the International Continence Society standardization subcommittee adopted a symptom-based definition in which urinary urgency was the key feature.² Currently, OAB is defined as urinary urgency, usually accompanied by frequency and nocturia, with or without urgency urinary incontinence, in the absence of urinary tract infection or other obvious pathologies.³ Urgency is the primary symptom, and urgency must be present for an OAB diagnosis to be made.^4,5 OAB can be further divided into “OAB dry,” which is OAB in the absence of urgency urinary incontinence, or “OAB wet,” which is OAB with associated urgency urinary incontinence.⁴

The reported prevalence of OAB varies widely depending on the sample studied, as well as study methodology and operational definitions.^{6

–16} Most studies have included primarily (or solely) older women, but there is, unfortunately, a paucity of research on younger, premenopausual women. Recent data from younger samples also show a wide prevalence range. Yeniel et al.¹⁴ reported OAB prevalence of 35.4% in female Turkish midwifery students aged 21.74 years ±2.15, whereas Van der Vaart et al.¹⁵ reported an 11.9% prevalence of OAB in Dutch women aged 20–45. Ergenoglu et al.¹⁶ found a high prevalence, 40.1%, in a small group of female Turkish nurses aged 37.8 ± 7.3 years, and Bradley et al. reported OAB prevalence of 22% in young female U.S. veterans (mean age 31.1 + 8.4 years) who had recently returned from combat.¹⁷

Many authors have reported that OAB has a significant negative impact on HRQoL, including negative influences on social, professional, and recreational activities, sleeping habits, and sexual activities.^{7,14
–16,18

–21} Most strikingly, individuals with OAB may experience a lower quality of life than people with diabetes,²² they experience depression at rates similar to people with diabetes or rheumatoid arthritis,²³ and they score lower on specific components of HRQoL than individuals with acquired immune deficiency syndrome (AIDS) or chronic obstructive pulmonary disease.²⁴ OAB is associated with increased rates of institutionalization in older adults,^23,24 and urinary frequency and nocturia have been shown to increase fall risk in older women.²⁵ People with OAB become preoccupied with identifying the closest bathroom, focus on defensive voiding (also known as “just in case” voiding), and restrict fluid intake in an effort to reduce the need to void.^20,26
–28 Again, most HRQoL data are on older women. Data on young women are limited and varied, but current research shows that OAB does negatively affect their HRQoL.^14
–16

There are numerous risk factors for OAB, such as increased age,^8,11,29 pelvic organ prolapse (POP),⁸ smoking,^8,30 surgery for urinary incontinence or POP,⁸ vaginal delivery,³¹ overweight (body mass index [BMI] ≥25),^8,10,32 and caffeine intake.^33,34 Alcohol, although often described as a bladder irritant in clinical practice, has been inconsistently associated with OAB symptoms in the literature.^31,32 Specific to risk factors in young women, Yeniel et al. reported an association between OAB symptoms and consumption of large quantities of caffeine or carbonated drinks.¹⁴ However, other risk factors in young women have not been fully explored, and could be different from those previously reported in older adults due to lower likelihood of issues such as POP or surgery for urinary incontinence.

Understanding OAB symptoms, their impact on HRQoL, and lifestyle factors associated with OAB in younger women is important to establish what should be considered normal or pathological for this group, as well as for influencing decisions regarding intervention. Therefore, the purposes of this study were to evaluate symptoms and characteristics of OAB as well as the effect of OAB on HRQoL in young female health profession students.

Methods

The study was a descriptive cross-sectional design with no random assignment and no control group. Institutional Review Board approval was obtained before the initiation of recruitment. All female students enrolled in the College of Health Professions (CHP) and the College of Optometry at a university in the Pacific Northwest (n = 964) were asked, via the primary author's communication with colleagues in each program, to attend in-person recruitment sessions between January and April 2013. Programs within the CHP included physical therapy, occupational therapy, physician assistant, pharmacy, psychology, dental health science, and healthcare administration. If in-person recruitment was not possible due to students' schedule restrictions, a recruitment email was sent out. A follow-up email was sent 1 month later, regardless of whether the initial recruitment was in-person or by email. Exclusion criteria were current pregnancy, urinary tract infection in the past 4 weeks, perimenopause, postmenopause, known POP, previous surgery for incontinence, or any neurological condition affecting bladder sensation, including stroke, multiple sclerosis, spinal cord injury, cauda equina syndrome, diabetes, or Parkinson's disease. Students who chose to participate in the study signed an informed consent form before completing the questionnaires.

Participants were asked to fill out three paper-based forms: the Overactive Bladder Questionnaire (OAB-q, 4-week recall version),³⁵ a 4-day bladder diary,^36,37 and a demographic information form. The OAB-q consists of a symptom bother scale, four HRQoL subscales (coping, concern, sleep, and social interaction), and a total HRQoL scale. Scores on each subscale range from 0 to 100 with higher symptom bother scores indicating greater symptom severity and higher HRQoL scores indicating better HRQoL.³⁵ The OAB-q is often used in intervention studies on patients with clinically diagnosed OAB, but the original validation study of the tool included a community sample who screened positive for OAB.³⁵

OAB was diagnosed based on 4-day paper-based bladder diary results; specifically, a participant was categorized as having OAB if she had an average of at least one episode of urgency per day.³⁸ There is no gold standard for diagnosing OAB and methods reported in the literature are highly variable, but as stated previously, urgency is considered the defining symptom. The bladder diary is a valid way to measure how often urgency occurs,⁵ and may be less susceptible to recall bias because it is being filled out as each event (void, fluid intake, and urgency) occurs.³² Diaries come in various forms (e.g., 1, 3, 4, and 7 days). For this study, the 4-day version was used because it is as reliable and valid as the 7-day version, but is less burdensome to participants.³⁷

Participants received standardized training on how to complete the bladder diary, including instructions to carry it with them and fill it out throughout the day, with the same verbiage used during in-person and email recruitment sessions. Urinary urgency was described on the bladder diary using the current definition.³⁹ Specifically, participants were told that “urgency is a feeling that comes on suddenly, making you want to rush to the bathroom because you fear that you may leak urine if you do not void right away.”³⁹ The difference between this and the normal sensation of urge that is felt when the bladder is full was also described during the in-person and email recruitment sessions. On the diary, participants indicated the presence of urgency by writing “yes” in the column “Was urgency present?” Participants also recorded the time of each void, and type of beverage consumed and amount (ounces), and incidents of urinary incontinence. The bladder diary was also used to identify frequency and nocturia. Frequency was defined as eight or more voids per 24 hours and nocturia was defined as waking one or more times per night to void.³⁹ To reduce participant burden and increase response rate, urinary output was not recorded. Finally, the demographic form included questions about age, height, weight, parity, number of vaginal births, and smoking. Data on race were not collected.

IBM SPSS Statistics data package was used for the data analysis (version 22; IBM, Armonk, NY). Difference between groups (OAB and non-OAB) for patient characteristics, bladder diary data, and OAB-q scores were compared with independent samples t-tests for continuous data and chi square or Fisher's exact test for categorical data. Significance was set at p < 0.05. Caffeine, alcohol, and carbonated drinks were considered irritants, and a unit of caffeine, alcohol, or carbonated drink was defined as one standard serving. If a beverage fell into multiple categories, it was counted as a unit in each category. For example, a 12 ounce cola drink was counted as a unit of caffeine and a unit of carbonated beverage (2 units of irritants total). Effect size was used to describe the magnitude of the difference between groups, with 0.2 considered minimal effect size, 0.5 moderate, and 0.8 large.⁴⁰

Results

A total of −210 participants completed the study (response rate 21.2%). No participants were excluded for menopause status, POP, or previous surgeries for incontinence. Four were excluded due to recent bladder infections, one due to diabetes, one because of a spinal cord injury, and one participant did not complete the OAB-q, leaving n = 203 for analysis. OAB was identified in 21.6% of the participants. Participant characteristics are presented in Table 1. There was no statistically significant difference in age, BMI, or vaginal births between participants identified as having OAB and those without OAB. Information on smoking was not analyzed or presented, as only one participant identified as a smoker.

Table 1.

Participant Characteristics, Overactive Bladder Versus Nonoveractive Bladder

	Total (n = 203), mean (SD)	OAB (n = 44), mean (SD)	Non-OAB (n = 159), mean (SD)	p
Age (years)	25.5 (3.7)	24.9 (3.3)	25.7 (3.8)	0.195^a
BMI (kg/m²)	22.5 (2.6)	22.4 (2.8)	22.5 (2.5)	0.691^a
Vaginal births (yes)	5	1	4	0.706^b

Independent samples t-test, equal variances assumed.

Fisher's exact test.

BMI, body mass index; non-OAB, nonoveractive bladder; OAB, overactive bladder; SD, standard deviation.

All participants filled out all 4 days of the bladder diary. Bladder diary data comparing participants with OAB and those without OAB are shown in Table 2. Data were normally distributed. Statistically significant differences between groups were found for episodes of urgency/24 hours (p = 0.001), units of caffeine/24 hours (p = 0.016), units of carbonated drinks/24 hours (p = 0.047), and total units of irritants/24 hours (p = 0.002); participants with OAB showed higher values in all of these categories. No statistically significant differences between groups were found for frequency, total voids, nocturia, incontinence, fluid intake, or alcohol intake, although they were all greater in the OAB group than the non-OAB group.

Table 2.

Four-day Bladder Diary Results, Overactive Bladder Versus Nonoveractive Bladder

	Total (n = 203), mean (SD)	OAB (n = 44), mean (SD)	Non-OAB (n = 159), mean (SD)	p
Frequency (% with symptom)	29.9	34.1	28.9	0.700
Total voids/24 hours	7.2 (2.5)	7.5 (2.2)	7.2 (2.5)	0.448
Nocturia (% with symptom)	42.9	50	40.1	0.265
Episodes of urgency/24 hours	0.6 (1.1)	2.2 (1.3)	0.1 (0.2)	0.001
Incontinence, any type (% with symptom)	4.4	6.8	3.8	0.409^a
Total fluid intake (oz.)/24 hours	69.3 (33.0)	69.8 (25.7)	69.1 (24.8)	0.902
Units caffeine/24 hours	1.6 (1.3)	2.0 (1.5)	1.5 (1.2)	0.016
Units alcohol/24 hours	0.4 (0.6)	0.5 (0.7)	0.3 (0.6)	0.092
Units carbonated drinks/24 hours	0.3 (0.5)	0.5 (0.6)	0.3 (0.5)	0.047
Total units of irritants/24 hours	2.3 (1.7)	3.1 (2.0)	2.1 (1.6)	0.002

Independent samples t-test for continuous data, equal variances assumed, data normally distributed; chi square for categorical data.

Fisher's exact test (<5 in one cell).

HRQoL was worse for participants with OAB than for those without OAB, as those with OAB showed statistically significantly worse results for every subscale of the OAB-q. Between-group effect sizes varied from medium (0.5) for sleep HRQoL to large (0.9) for symptom bother. Full OAB-q results are shown in Table 3.

Table 3.

Overactive Bladder Questionnaire Results, Overactive Bladder Versus Nonoveractive Bladder

	Total (n = 203), mean (SD)	OAB (n = 44), mean (SD)	Non-OAB (n = 159), mean (SD)	p^a	Difference between group means (95% CI)	Between-group effect size (95% CI)
Symptom bother	12.8 (13.7)	21.7 (15.4)	10.3 (12.1)	0.001	11.4 (7.6, 15.2)	0.9 (0.5, 1.2)
Coping HRQoL	95.6 (10.2)	89.9 (14.4)	97.1 (8.0)	0.001	7.2 (4.3, 10.1)	0.7 (0.4, 1.1)
Concern HRQoL	93.3 (11.5)	86.8 (14.1)	95.1 (9.9)	0.001	8.3 (5.0, 11.6)	0.8 (0.4, 1.1)
Sleep HRQoL	91.9 (11.4)	87.3 (14.2)	93.2 (10.3)	0.01	5.9 (2.6, 9.3)	0.5 (0.2, 0.9)
Social HRQoL	98.9 (4.3)	96.9 (6.9)	99.4 (3.0)	0.025	2.5 (1.3, 3.7)	0.6 (0.3, 0.9)
Total HRQoL	94.9 (7.6)	89.9 (10.5)	96.3 (5.9)	0.001	6.4 (4.3, 8.5)	0.9 (0.6, 1.2)

Higher symptom bother scores are indicative of greater symptom severity, and higher HRQoL scores are indicative of better HRQoL.

Equal variance not assumed.

CI, confidence interval; HRQoL, health-related quality of life.

Discussion

Many components of OAB were examined in this study. Although the relative homogeneity of the study sample (young, mostly nulliparous, healthy, well-educated women with normal BMIs) limits comparison with the results of other studies, it allows for closer examination of the relevant differences that exist within this sample between those with OAB and those without OAB. Of all of the risk factors for OAB that were examined in this study, the only statistically significant differences were in consumption of carbonated drinks, caffeine, and total units of bladder irritants, with participants with OAB consuming more of all three than participants without OAB.

This study may be unique in its comprehensive bladder diary results, which allowed for detailed analysis of all symptoms of OAB as well as fluid intake and bladder irritants. Although bladder diaries are clinically useful for assessing voiding habits, urinary symptoms, and fluid intake, they are burdensome for researchers to analyze. Therefore, researchers usually favor symptom recall questionnaires due to their ease of administration. However, questionnaires may not be as accurate due to recall bias.⁴¹ Although it is possible that the bladder diaries used in this study were not entirely accurate, participants were specifically asked to fill them out in real time in an effort to make them as accurate as possible, and all participants completed full 4-day bladder diaries.

HRQoL was lower in participants with OAB than in those without OAB. The largest difference in HRQoL between groups was on the symptom bother subscale (11.4 point difference, effect size 0.9). Differences in HRQoL between participants with OAB wet and OAB dry were not analyzed due to the low number of participants with OAB wet (n = 3). Results in this study indicating lower HRQoL are consistent with those reported by other authors^14,15; however, a clear comparison of results is difficult due to variations in sample characteristics, diagnostic criteria, methods used, and outcome measures.

Although it was not possible to track nonresponders, there was significant variability in response rate among programs (from 79% in physical therapy to 2% in psychology). One possible reason for this was the method of recruitment; all physical therapy recruitment sessions were performed in-person, but for other programs a variable number were done via email (including 100% of sessions for the psychology program) due to conflicts from course schedules. In addition, the author responsible for recruiting participants was from the physical therapy department, which may have motivated students from that department to participate in the study. This variability, combined with the small samples from several programs, prevented comparisons among programs.

This study has several notable strengths. It addresses OAB in a previously understudied population, with a focus on lifestyle factors that may impact OAB. Therefore, it may provide an entry point for examining underexplored aspects of OAB. Considering the high rates of anxiety, depression, and decreased HRQoL, combined with the increased risk of other health problems for people with OAB and the overall public health concern created by OAB, it is clear that accurate identification of individuals with OAB is very important. Identification can lead to proper treatment, thereby allowing an individual to avoid the negative health consequences of OAB already described. Another strength is that, as previously mentioned, this study included in-depth bladder diary analysis, which allowed detailed examination of differences in consumption of bladder irritants between groups. Finally, use of valid outcome measures and easy-to-reproduce operational definitions makes follow-up studies feasible.

Limitations of the study include the low overall response rate, variable response rate among programs, and small number of participants. Also, the study was carried out on a small sample of a specific subset of the population. Therefore, caution must be used when applying results to other groups. In addition, although bladder diaries have been shown to be reliable (as already described), they still may be subject to inaccuracies. Also, no multivariate analysis was done, and differences in fluid consumption habits between the groups could have been explained by factors that were not measured (e.g., exercise habits). Finally, selection bias could have been a factor if women who had OAB symptoms were more interested in the study and, therefore, more likely to participate.

Conclusion

Results from this study indicate that OAB symptoms and their impact on HRQoL are relevant for female health profession students. In this study on young, generally nulliparous, well-educated, healthy women, those with OAB (defined by the presence of urgency) consumed more caffeine and carbonated beverages than women without OAB, and OAB had a significant effect on HRQoL.

Future studies should include examination of larger groups of young women from different backgrounds. The association between bladder irritants and OAB should be further explored in intervention studies to see whether elimination of irritants would reduce OAB symptoms. Finally, education about OAB and therapeutic options for OAB could be explored to examine the effects on HRQoL in young women with OAB.

Footnotes

Acknowledgments

The authors would like to thank Blake Osmundsen, MD, and Kevin Chui, PT, DPT, PhD, for their assistance in reviewing drafts of this article.

Author Disclosure Statement

No competing financial interests exist.

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