Urinary Incontinence, Depression, and Economic Outcomes in a Cohort of Women Between the Ages of 54 and 65

Abstract

Objective

To estimate the association between urinary incontinence and probable depression, work disability, and workforce exit.

Methods

The analytic sample consisted of 4,511 women enrolled in the population-based Health and Retirement Study cohort. The analysis baseline was 1996, the year that questions about urinary incontinence were added to the survey instrument, and at which time study participants were 54–65 years of age. Women were followed with biennial interviews until 2010–2011. Outcomes of interest were onset of probable depression, work disability, and workforce exit. Urinary incontinence was specified in different ways based on questions about experience and frequency of urine loss. We fit Cox proportional hazards regression models to the data, adjusting the estimates for baseline socio-demographic and health status variables previously found to confound the association between urinary incontinence and the outcomes of interest.

Results

At baseline, 727 participants (survey-weighted prevalence, 16.6 percent; 95% confidence interval [CI], 15.4–18.0) reported any urinary incontinence, of which 212 (survey-weighted prevalence, 29.2 percent; 95% CI, 25.4–33.3) reported urine loss on more than 15 days in the past month; and 1,052 participants were categorized as having probable depression (survey-weighted prevalence, 21.6 percent; 95% CI, 19.8–23.6). Urinary incontinence was associated with increased risks for probable depression (adjusted hazard ratio [AHR], 1.43; 95% CI, 1.27–1.62) and work disability (AHR, 1.21; 95% CI, 1.01–1.45) but not workforce exit (AHR, 1.06; 95% CI, 0.93–1.21).

Conclusions

In a population-based cohort of women between the ages of 54 and 65, urinary incontinence was associated with increased risks for probable depression and work disability. Improved diagnosis and management of urinary incontinence may yield significant economic and psychosocial benefits.

INTRODUCTION

Urinary incontinence is a common condition affecting nearly one-fifth of women in the U.S. [1]. The symptoms can be extremely bothersome [2] and may be accompanied by numerous adverse psychosocial sequelae, including social isolation [3] and depression [4]. Overall, women with urinary incontinence experience substantially reduced quality of life [5, 6]. In comparison, less is known about the economic impacts of urinary incontinence. Estimates of the volume and aggregate cost of urogynecological procedures do not account for indirect costs such as those related to lost economic productivity [6, 7]. Women with urinary incontinence adopt numerous strategies to manage symptoms at work, but their symptoms nonetheless compromise their self-confidence, concentration, and/or work performance [2, 8–11]. Women faced with these difficulties may decide to engage in limited types of work or to work fewer hours, or even exit the workforce entirely.

Understanding the indirect costs of urinary incontinence as reflected in labor force outcomes has long been highlighted as an important area for investigation [7, 8]. While the cross-sectional studies cited above suggest that urinary incontinence may have important negative impacts on economic outcomes, they are far from conclusive. To address this important gap in the literature, we conducted a secondary analysis of data from the Health and Retirement Study, an ongoing population-based cohort of middle-aged and older adults. Given their high risk not only for transitions out of the workforce but also urinary incontinence [1] and depression [12], this age group represents an important population for in-depth study of the relationships between these variables. Specifically, we sought to estimate the association between urinary incontinence and risk of depression, work disability, and workforce exit over long-term follow-up.

METHODS

The Health and Retirement Study employs a multi-stage area probability sample and at its inception in 1992 had a target population of all adults aged 51–61 years residing in households in the contiguous United States [13]. Data are collected through biennial telephone and in-person interviews. The response rate to the initial survey was 81.6 percent, and re-interview response rates have exceeded 93.1 percent at every subsequent interview cycle. The omnibus questionnaires administered to study participants reflect a broad range of analytic and policy interests related to labor force, health, and family transitions. Because of its expansive scope and sampling strategy, the Health and Retirement Study is frequently used by analysts to investigate questions of clinical relevance to the gynecologic care of middle aged and older women [3, 4, 10, 14, 15] and to middle aged and older adults in general [16–18].

Because questions about the primary exposure of interest (urinary incontinence) were not added to the surveys until 1996, we restricted our analysis to data beginning in 1996, by which time study participants were 54–65 years old. Urinary incontinence was assessed with the question, “This might not be easy to talk about, but during the last 12 months, have you lost any amount of urine beyond your control?” Participants who responded affirmatively were then asked to estimate the frequency of episodes with the question, “On about how many days in the last month have you lost any urine?” Responses were grouped into three ordered categories (none/continent, 0–15 days, and >15 days), which allowed us to explore potential dose-dependence in the associations between urinary incontinence and the outcomes of interest.

The primary outcomes of interest were onset of probable depression, work disability, and workforce exit. Depression symptom severity was measured using a modified version of the Center for Epidemiologic Studies-Depression scale [19], shortened to eight items while retaining similar reliability [20, 21], factor structure [21], and construct validity [21–23]. Although the diagnosis of major depressive disorder is a clinical diagnosis that accounts for other pertinent information such as symptom duration, functional impairment, and exclusion of other psychiatric diagnoses, participants’ survey responses enabled us to identify probable depression with reasonable accuracy. Specifically, a score ≥3 on the Center for Epidemiologic Studies-Depression scale was used to classify study participants as having symptoms indicating probable depression. This threshold has been found to have 71 percent sensitivity and 79 percent specificity when compared to the criterion standard of major depression as determined by the short form of the World Health Organization Composite International Diagnostic Interview [21, 24].

The outcome of work disability was assessed with the question, “Do you have any impairment or health problem that limits the kind or amount of paid work you can do?” Responses are scored on a dichotomous scale, i.e., “yes” or “no.” Its construct validity is supported by prior studies correlating work disability with pain [23] and labor force participation [25]. Furthermore, little bias was observed when the responses of Health and Retirement Study participants were compared to the criterion standard of U.S. Social Security Administration disability insurance benefit decisions [26]. The outcome of workforce exit was based on the “labor force status” variable in the RAND Health and Retirement Study Data file [27], which summarizes the labor force status for each respondent at each interview into mutually exclusive categories of “working full-time,” “working part-time,” “unemployed,” “partly retired,” “retired,” “disabled,” or “not in the labor force” [28]. Workforce exit was defined as being retired, partly retired, disabled, or not in the labor force.

For each of the 3 outcomes, we fit 2 Cox proportional hazards regression models corresponding to the 2 different specifications of urinary incontinence described above. Analysis time was extended through 2010–11. Estimates were adjusted for the following socio-demographic and health status variables measured at baseline: age, race, marital status, educational attainment, household income, body mass index, parity, smoking status, alcohol use, psychiatric medication use, number of physician-diagnosed chronic conditions out of eight (hypertension, diabetes, cancer, chronic lung disease, cardiovascular disease, cerebrovascular disease, arthritis, or psychiatric disorder), and difficulties with activities of daily living. In these regression models, the sub-sample of participants initially considered “at risk” varied by outcome. For the analyses examining onset of probable depression, only participants who had no depressive symptoms or who had subthreshold symptoms (modified depression score <3) at baseline were considered “at risk” for developing the outcome over the follow-up period. For the analyses examining onset of work disability, we limited the analytic sample to participants with no work disability at baseline. Finally, for the analyses examining workforce exit, we excluded participants who were not in the labor force at baseline (i.e., they reported being retired, partly retired, or not in the labor force).

For each multivariable regression model, the link test proposed by Pregibon [29, 30] was employed to assess adequacy in specification of the linear predictor. Namely, after estimation of the regression coefficients, the linear predictor and its square were included in a second version of the regression model. A non-statistically significant estimated regression coefficient on the square of the prediction was taken to be evidence that the proportional hazards assumption was not violated. No violations were noted. All analyses were conducted with the use of the Stata statistical software (version 13.0, StataCorp LP, College Station, Tex.) and employed the survey weights to adjust standard errors for the complex survey sampling design. Due to survey weighting, some prevalence estimates may not correspond exactly to the ratio of the subpopulation to the sample size and are explicitly labeled below.

Study participants provided written informed consent. Health and Retirement Study procedures were approved by the relevant committees at the University of Michigan and the U.S. National Institute of Aging. The data have been made publicly available for download at http://hrsonline.isr.umich.edu/ as unrestricted datasets, which are purged of secondary identifying information such that they pose no significant threat to respondent anonymity. The specific analysis presented in this paper was reviewed by the Partners Human Research Committee and determined not to meet the definition of human subjects research because it was based on anonymous, public-use data with no identifiable information on study participants.

RESULTS

Summary statistics for the sample are described in Table 1. The analytic sample consisted of 4,511 women. The mean age was 59.4 years. The sample consisted largely of Caucasian women, only a minority of whom did not complete high school. Most women reported having three or more children.

Table 1.

Summary Statistics (N=4,511)

	Mean (Range) or Percentage (95% Confidence Interval)
Age (y)	59.4 (54–65)
Race
White/Caucasian	85.7% (84.0–87.3)
Black/African-American	10.7% (9.5–11.9)
Other	3.6% (2.9–4.6)
Married	68.1% (66.4–69.7)
Educational Attainment
Did Not Complete High School	28.0% (25.4–30.9)
High School Graduate	37.2% (35.6–38.9)
Some College	20.0% (18.6–21.5)
College Graduate or More	14.7% (13.1–16.5)
Household Income
Quintile 1 (Poorest)	6778 (0–12440)
Quintile 2	18789 (12444–25000)
Quintile 3	32357 (25024–40492)
Quintile 4	51853 (40500–65940)
Quintile 5 (Richest)	130054 (66000–1116086)
Body Mass Index
<18.5 kg/m2	17.3 (13.7–18.4)
18.5–24.9 kg/m2	22.5 (18.5–24.9)
25–29.9 kg/m2	27.2 (25–29.9)
≥30 kg/m2	34.6 (30–63.5)
Parity
Nulliparous	8.4% (7.7–9.2)
One Child	8.9% (7.9–9.9)
Two Children	24.7% (23.1–26.3)
Three Children or More	58.1% (56.2–60.0)
Currently Smokes	19.8% (18.4–21.2)
Currently Uses Any Alcohol	47.0% (44.2–49.7)
Number of Chronic Conditions
None or One	61.1% (59.2–63.1)
Two or More	38.9% (36.9–40.8)
Difficulty with Any Activities of Daily Living	11.4% (10.3–12.5)
Use of Any Psychiatric Medication	8.0% (7.1–9.0)

Among all study participants, 727 (survey-weighted prevalence, 16.6 percent; 95% confidence interval [CI], 15.4–18.0) reported any urinary incontinence at baseline. Of these, 212 participants (survey-weighted prevalence, 29.2 percent; 95% CI, 25.4–33.3) reported losing urine on more than 15 days out of the past month. A total of 1,052 participants were categorized as having probable depression (survey-weighted prevalence, 21.6 percent; 95% CI, 19.8–23.6) and 1,276 participants had a work disability (survey-weighted prevalence, 27.1 percent; 95% CI, 25.4–28.9), while 1,921 participants were working for pay, either full time or part-time (survey-weighted prevalence, 43.0 percent; 95% CI, 41.4–44.5); these participants were excluded from the survival analyses depending on the model specification (described below).

Analytically, women were followed from November 15, 1995 to May 15, 2011. Among the 3,300 women with absent or subthreshold symptoms of depression at baseline, 1,628 developed probable depression (49.3%). Presence of urinary incontinence was associated with an increased risk of probable depression (adjusted hazard ratio [AHR], 1.43; 95% CI, 1.27–1.62) (Table 2). Increasing frequency of incontinence (in terms of days with urine loss) was associated with greater risk.

Table 2.

Adjusted Associations between Urinary Incontinence and Time to Probable Depression, Work Disability, and Workforce Exit

	Adjusted Hazard Ratio (95% Confidence Interval)
	Probable Depression (n=3,300)	Work Disability (n=3,075)	Workforce Exit (n=1,848)
Urinary Incontinence
No	Ref	Ref	Ref
Yes	1.43 (1.27–1.62) ‡	1.21 (1.01–1.45) *	1.06 (0.93–1.21)
Number of Days of Urine Loss
Continent	Ref	Ref	Ref
≤15 Days	1.24 (1.07–1.43) †	1.38 (1.20–1.59) ‡	1.03 (0.88–1.21)
>15 Days	1.89 (1.60–2.22) ‡	2.01 (1.58–2.56) ‡	1.14 (0.93–1.40)

This table represents the output of 2 regression models for each of the 3 outcomes, specifying the different urinary incontinence variables as the explanatory variable of interest while adjusting for baseline age, race, marital status, educational attainment, household income, body mass index, parity, current smoking status, current alcohol use, number of chronic conditions, difficulties with activities of daily living, and current use of psychiatric medications.

^*Statistical significance at the level of P<.05

^†Statistical significance at the level of P<.01

^‡Statistical significance at the level of P<.001

Among the 3,075 women with no work disability at baseline, 1,398 developed a new work disability (45.5%). Presence of urinary incontinence was associated with an increased risk of work disability (AHR=1.21; 95% CI, 1.01–1.45), with increasing frequency of incontinence similarly associated with greater risk. Among the 1,848 women working full time or part time at baseline, 1,621 left the workforce (87.7%). Regardless of how the exposure was defined, urinary incontinence did not have a statistically significant association with workforce exit.

DISCUSSION

In this national cohort of women between the ages of 54 and 65 in the U.S. followed over 14 years, we found that urinary incontinence was associated with increased risks for probable depression and work disability but not workforce exit. The estimated associations were statistically significant, large in magnitude, increasing in severity of the exposure, consistent with related strands of research, and robust to the inclusion of confounders previously found to be related to both the exposures and outcomes. Our findings have important implications for both research and clinical practice in this area.

The potential association between depression and either urinary incontinence or the severity of incontinence has been well-studied. Most analyses in this literature have been cross-sectional in nature [4, 31–33], but two longitudinal studies have shown null findings [15, 34]. Thom et al. [34] measured urinary incontinence using chart diagnoses, but it is well known that fewer than one-half of women with urine leakage actually seek care for their symptoms [35]. The analysis by Melville et al. [15] was based on the same underlying dataset as ours, but we believe there are four potential explanations for the conflicting findings. First, in estimating the association between urinary incontinence measured in 1996 and probable depression measured during 1998–2004, Melville et al. [15] did not account for attrition from the study during the eight-year period. Second, our use of repeated-measures, time-updated data on urinary incontinence minimized the potential for misclassification of exposure status (that would have occurred had a study participant’s exposure status changed after the baseline interview). Third, in our analysis, the participants were followed for a longer duration of time. The Cox proportional hazards regression models likely provided greater statistical power than the logistic regression model of Melville et al. [15], as study participants contributed data until they experienced the outcome of interest or exited the study. Fourth, Melville et al. [15] employed a different threshold on the depression scale (i.e., with ≥6 indicating probable depression). Any of these analytic modifications, either alone or in combination with the others, could have explained the discrepant results.

A second important finding is that urinary incontinence predicted the development of a work disability. Given that previous work has shown depression to be one of the most important causes of work absenteeism [36, 37], the analysis presented here extends previously published findings that only indirectly suggest the potential adverse labor force impacts of urinary incontinence [2, 8–11]. The mechanisms explaining the association between urinary incontinence and work disability are likely varied and may be due to symptom-related bother [8, 9], avoidance and limiting behaviors [2], or restricted physical activities in general [10, 11]. Importantly, there was no statistically significant association between urinary incontinence and workforce exit. It may be that the threshold for exiting the workforce due to incontinence-related bother may be higher than the threshold for engaging in different types of work or cutting back on the amount of work.

If these estimated associations are causal, the findings presented in this analysis suggest that early diagnosis and management of urinary incontinence may have important psychosocial and economic benefits for women. Given that depression is a treatable condition, obstetricians and urogynecologists should be attentive to its signs and/or symptoms among their patients presenting with urinary incontinence. With regard to the study’s economic implications, some observers may ask how many more years of economic productivity the women in this study have to contribute. However, if effective management of urinary incontinence prevents the loss of only one -- and potentially up to 11 -- years of economic productivity (i.e., prior to Medicare eligibility), this could still have important economic consequences for individual women. At the level of population health, the macroeconomic implications for the U.S. would depend on the aggregate number of women with urinary incontinence for whom effective intervention delayed or prevented their reliance on public insurance programs like Medicare and/or Social Security Disability Insurance. Certainly the analyses presented here cannot establish causality. It may be that urinary incontinence is simply a marker for frailty heralding subsequent functional decline [38], but this would not undermine the economic benefits of early diagnosis and management.

Interpretation of our findings is subject to several limitations. First, the analytic sample consisted of a relatively homogeneous group of women with an age range of 54–65 years at baseline. On average they may have fewer economically productive years compared to younger women, so it is likely that the potential economic impacts identified in our study are minimized. Urinary incontinence is likely to exert even more powerful labor force effects at younger ages and among women of lower socioeconomic status, but this possibility would need to be explored with a different dataset. Second, all of the variables were self-reported. Notably, labor force participation was not verified with employer surveys or access to employment records. However, it is also important to note that the outcome measures were generic rather than condition-specific. To the extent that outcome measures based on condition-specific questions (e.g., “Does fear of odor or smell restrict your activities?” [39]) would have been more closely correlated with urinary incontinence [31, 40], our estimates are likely biased towards the null. Third, this analysis did not distinguish between different types of incontinence. To the extent that urge urinary incontinence has greater adverse effects on quality of life compared to stress urinary incontinence [41–43], the estimates presented here may be biased towards the null. Finally, although the outcome of probable depression (as determined by responses to a screening instrument) is accepted in the field and is frequently used in large-scale epidemiologic studies [4, 15], it does not equate to a clinical diagnosis of major depressive disorder or dysthymia consistent with the Diagnostic and Statistical Manual of Mental Disorders To explore the sensitivity of our findings to alternative definitions of probable depression, we used a threshold of ≥4 on the Center for Epidemiologic Studies-Depression scale, which is the threshold estimated by Steffick [44] to correspond to the conventionally adopted threshold of ≥16 on the full 20-item scale [19, 45]. This procedure actually yielded point estimates of increased magnitude and statistical significance, so we chose to report the more conservative estimates in this article.

These caveats notwithstanding, our analysis of population-based, longitudinal data shows that urinary incontinence among women between the ages of 54 and 65 is associated with increased risks for onset of probable depression and work disability. These findings are unlikely to be explained entirely by unobserved confounding and, if anything, are stronger and of greater magnitude than the estimates presented here. Therefore, improved diagnosis and management of urinary incontinence may yield significant economic and psychosocial benefits.