Background
Impaired cognition has been correlated with adverse postoperative outcomes, such as an increased incidence of delirium, a longer length of hospital stay, and higher 6 month mortality. The incidence of cognitive impairment in the elderly is high. Per the Centers for Disease Control and Prevention, 1 in 8 adults aged 60 years and older deal with memory loss and confusion, and less than 20% inform their health care providers. Most studies in the elderly or cognitively impaired have been conducted at Veterans Administration hospitals, in which the majority of patients are male. As the female patient population ages, it is increasingly important to describe the prevalence of cognitive impairment in this specific population as well as identify and manage risk factors for cognitive decline in the ambulatory and perioperative setting.
Objective
The objective of the study was to determine the prevalence of positive screening for cognitive impairment in a urogynecology ambulatory population and to establish the feasibility of using standardized, validated screening questionnaires in a tertiary care setting.
Study Design
After institutional review board approval, all English-speaking patients 65 years old or older presenting to our ambulatory urogynecology clinic were invited to participate. Cognitive impairment was assessed using both the validated Mini-Cog test and the Eight-Item Interview to Differentiate Aging and Dementia screen for mild dementia. A Mini-Cog score <3 suggests cognitive impairment, whereas an Eight-Item Interview to Differentiate Aging and Dementia score of ≥2 discriminates dementia from normal cognition. Because of the association of depression and cognition in the elderly, the Geriatric Depression Scale (short form of 15 items) was administered, with a score >5 suggesting depression. Demographic and medical history were abstracted from the medical record.
Results
A total of 371 subjects were asked to participate (39 were excluded and 37 declined); 295 subjects (79.5%) were included in the study. Mean subject age was 74.5 years, and 96.6% were white, with an average of 4.1 chronic medical comorbidities. Cognitive impairment was identified in all age groups per the Mini-Cog as follows: 65–74 years, 5.3%; 75–84 years, 13.7%; and 85 years and older, 30%. There was a significant difference in the positive screen for cognitive impairment between ages 65–74 vs >75 ( P ≤ .001). According to the Eight-Item Interview to Differentiate Aging and Dementia, all 3 age groups perceived themselves to have early cognitive changes: 65–74 years, 25.9%; 75–84 years, 31.9%; and 85 years and older, 40% ( P = .231). The most commonly identified areas of impairment were having daily problems with thinking and memory (62%), problems with judgment (52%), and trouble learning new tools or gadgets (44%). There was no difference in the number of patients who screened positive for depression across age groups: 65–74 years, 5.9%; 75–84 years, 6.3%; and 85 years and older, 10% ( P = .697).
Conclusion
In our study population positive screening for cognitive impairment, as measured by validated questionnaires, was prevalent among women aged >75 years. Screening for potential cognitive impairment in an ambulatory urogynecology population is feasible and useful in clinical practice. Our subjects were interested in cognitive screening because a third of them self-reported early cognitive changes. These tools are effective in screening for previously unrecognized impaired cognition, a definitive diagnosis, and hence treatment requires additional evaluation. Future studies could evaluate which screening tools for cognitive impairment would be most helpful in assessing patients prior to surgery in an effort to further decrease perioperative morbidity in elderly woman.
By the year 2050, the number of women over the age of 65 years is predicted to increase by greater than 40%, whereas the number of women over the age of 85 years will more than double. The incidence of cognitive impairment in the elderly is high. Per the Centers for Disease Control and Prevention, 1 in 8 adults aged 60 years old and older deal with memory loss and confusion and less than 20% inform their health care providers.
Advanced age alone carries an increased risk of perioperative morbidity and mortality. Impaired cognition has also been correlated with adverse postoperative health outcomes, including an increased incidence of complications, delirium, a longer length of hospital stay, and higher 6 month mortality. Thus, more emphasis is being directed at cognition testing in the standard panel of preoperative risk assessment testing.
As the female patient population ages, the number of surgeries to correct pelvic floor disorders has been predicted to increase by nearly 48% by 2050. Thus, it has become increasingly important to identify and manage risk factors preoperatively that could affect postoperative outcomes. The majority of studies on the elderly or cognitively impaired have been conducted at Veterans Administration hospitals in which the majority of patients are male.
Three studies have demonstrated elderly women undergoing urogynecological procedures have an increased risk of morbidity and mortality. However, no studies have examined baseline cognition in this specific population or the impact of preoperative impaired cognition on postoperative outcomes. Studies in the general surgery literature reveal that cognitive impairment independently predicts adverse postoperative outcome. Robinson et al found that baseline cognitive impairment in older patients, as measured by the Mini-Cog test, undergoing major elective operations was associated with increased postoperative complications, length of hospital stay, and long-term mortality. A joint best practice guideline statement from the American College of Surgeons and the American Geriatrics Society recommends assessing the baseline cognitive ability and functional status for all older patients undergoing surgical procedures.
The primary aim of this study was to estimate the prevalence of screening positive for cognitive impairment in an urogynecology ambulatory population. A secondary aim was to establish the feasibility of using standardized, validated screening questionnaires in a tertiary care setting. An additional secondary aim was to investigate the prevalence of a positive depression screen in this population to facilitate our interpretation of our primary aim results.
Materials and Methods
After institutional review board approval, all English-speaking patients 65 years old or older, presenting to our ambulatory urogynecology clinic were invited to participate in this observational cross-sectional study. Two cognitive-impairment screening tests and 1 depression screening test were administered by non–physician-trained members of our research team.
Exclusion criteria included all patients with a self-reported or documented preexisting diagnosis of cognitive impairment and/or dementia, patients with active psychotic disorders, acute or unstable medical conditions, recent neurological injury or neurological disorders, current alcohol or other drug abuse, chronic narcotic use, non–English-speaking patients, and those who were unable to participate secondary to severe hearing or visual impairment and/or illiteracy.
Participants were enrolled from August 2013 to July 2015. All participants gave informed consent. Baseline patient characteristics were abstracted from the electronic medical record, including participant age, sex, race, education, number of chronic medical conditions, number of medications, employment status, marital status, and history of head injury. We also verified this information with the participants while administering the screening instruments described in the following text. We specifically collected data from the electronic medical record relating to preexisting cardiovascular disease including tobacco use, history of cerebrovascular accident, hypertension, diabetes, and hyperlipidemia.
A trained member of the research team administered the Mini-Cog, the Eight-item Interview to Differentiate Aging and Dementia, and the Geriatric Depression Scale. The participants received brief instructions on how to complete the 3 surveys at the beginning of the encounter. No additional assistance was required except during the word recall portion of the Mini-Cog.
The Mini-Cog is a validated screening tool for the detection of cognitive impairment. The Mini-Cog is considered to be a reasonable, shorter screening alternative to the copyright-restricted Mini-Mental Status Examination for identifying patients with possible cognitive impairment.
The Mini-Cog consists of a 3 item recall to assess memory and a clock-drawing test to assess executive function while also serving as a distractor. The clock-drawing test is assessed as normal (2 points) or abnormal (0 points). The standard algorithm was used to score the Mini-Cog: scores range from 0 to 5, with scores from 0 to 2 considered probably impaired and scores 3 to 5 considered probably not impaired. Mini-Cog administration time is approximately 3 minutes per previously published studies.
The Mini-Cog is a performance-based tool that is recommended for cognitive screening in primary health care. However, experts have commented that the utility of performance-based cognitive screening tools may be limited by education and cultural factors. For this reason, we also included an informant-based cognitive screening tool, the Eight-Item Interview to Differentiate Aging and Dementia, which has been described as more sensitive for detecting early dementia, less likely to be influenced by the acute condition of the patient, and may complement performance-based tools when used in combination. In addition, the Eight-Item Interview to Differentiate Aging and Dementia informant-based, 8-item dementia screening instrument is brief (<3 minutes) and has excellent discriminant ability and biological validity. The Eight-Item Interview to Differentiate Aging and Dementia has been validated for cognitive screening in tertiary health care settings.
The Eight-item Interview to Differentiate Aging and Dementia consists of 8 yes/no questions that are self-administered by the participant without the assistance of medical or research staff. It typically takes 2–3 minutes to complete. The Eight-item Interview to Differentiate Aging and Dementia questionnaire targets the participant’s perception of her memory, problem-solving abilities, orientation, and impact of cognitive function on daily activities over the past several years. It is a screening test for very mild cognitive impairment. The 8 items are added, resulting in a score ranging from 0 to 8. The suggested cutoff score for dementia is 2 or greater.
Because of the association of depression and cognition in the elderly, the Geriatric Depression Scale (short form) was also administered to all. This is a validated 15 item, self-administered questionnaire, which asks participants yes/no questions about their feelings, daily activities, energy, and basic satisfaction with life. Participants answer yes or no and receive points for these responses per a standard algorithm. A score of 6 or more suggests depression. This typically takes 2–3 minutes to complete.
Participants were informed of the results of their screening tests, and we recommended further diagnostic cognitive testing to those that screened positive. In this study we did not evaluate information gathered from the additional neuropsychological evaluation of participants with positive screening because the primary aim of the study was to assess the prevalence and feasibility of cognitive impairment screening in an ambulatory setting.
Our sample size was calculated using an estimated 20% prevalence of cognitive impairment in our patient population, based on data from large studies estimating the prevalence of cognitive impairment in the United States. Using an alpha error of 0.05 and a confidence interval of 95%, a sample size of 246 patients was calculated. To account for an expected 15-20% rate of refusal to participate, we planned to recruit 20% more subjects, with a goal of recruitment of a total of 295 subjects.
All analyses were performed using SPSS software (SPSS Inc, Chicago, IL). Descriptive statistics were used to characterize the sample. The prevalence of positive screening for cognitive impairment and depression was calculated for our entire patient population and by age group. Categorical variables were expressed as counts and percentages. χ 2 tests and odds ratios were used to test for associations.
Results
A total of 371 patients were invited to participate in the study, 295 (79.5%) completed the cognitive and depression assessment, and 37 patients declined to participate. Thirty-nine subjects were excluded; the most common reasons for exclusion were an inability to speak or understand English (17.1%), an established diagnosis of dementia (15.8%), and/or a history of neurological injury or disorder (7.9%), which affected their memory or ability to fully participate in the study.
Among the women who participated in the study, the mean age was 74.5 ± 6.9 years, and 96.6% were white ( Table 1 ). On average, subjects had 4.1 ± 2.6 chronic medical conditions. The most common medical conditions included hypertension (65.8%), hyperlipidemia (56.3%), and diabetes mellitus (14.6%). Subjects on average were taking 5.5 medications for their chronic conditions. Sixty-one of the subjects (20.7%) had a past medical history of depression. Those excluded from the study were comparable in mean age but were more likely to be of other race, especially Hispanic (10.5%). It took approximately 10 minutes for the participants to complete all 3 screening tools. On average each survey took approximately 3 minutes.
| Characteristics | n, % |
|---|---|
| Total subjects | 295 |
| Age, y, mean ± SD | 74.5 ± 6.9 |
| Race | |
| White | 285 (96.6) |
| African-American | 9 (3.1) |
| Asian | 1 (0.3) |
| Medical conditions | |
| Hypertension | 194 (65.8) |
| Diabetes mellitus | 43 (14.6) |
| Hyperlipidemia | 166 (56.3) |
| Head injury | 29 (9.8) |
| Stroke | 10 (3.4) |
| Depression | 61 (20.7) |
| Number of chronic medications, mean ± SD | 5.5 ± 3.3 |
| Ever smoked | 98 (33.2) |
| Pack-years, median (IQR) | 10 (20.5) |
| Marital status | |
| Married | 182 (61.7) |
| Divorced, separated | 30 (10.2) |
| Widowed | 68 (23.1) |
| Never married | 15 (5.1) |
| Education, y | |
| <1 | 28 (9.6) |
| 12 | 82 (28.0) |
| >12 | 183 (62.4) |
| Employed | |
| Currently employed | 49 (17.4) |
| Never employed, retired | 233 (82.6) |
Overall 10.5% of the subjects (n = 31) screened positive for cognitive impairment on the Mini-Cog assessment, with a score of 0–2 of 5. As shown on Table 2 , positive screening was identified in all 3 age groups: 65–74 years, 5.3%; 75–84 years, 13.7%; and 85 years or older, 30%. There was a significant difference in cognitive impairment by age: 65–74 years vs >75 years ( P ≤ .001). Patients who had greater than 12 years of education were less likely to screen positive for cognitive impairment ( P = .004). Forty-three of the 295 participants (14.6%) failed the clock drawing test portion of the Mini-Cog. However, 13 of 43 (30.2%) ultimately screened negative for cognitive impairment because of their perfect recall score. Almost all patients who screened positive for cognitive impairment on the Mini-Cog (96.8%) failed the clock drawing test.
