Laura E. Gibbons

Assessing quality of life in older adults with cognitive impairment

Objective This article discusses theoretical, psychometric, and practical considerations of quality of life assessment in older adults with cognitive impairment. It describes a new measure of quality of life in dementia, the QOL-AD, and examines the reliability and validity of patient and caregiver reports of patient quality of life. Methods Subjects were 177 patient/caregiver dyads. Patient Mini Mental State Exam scores ranged from 0 to 29, with a mean score of 16 (SD = 7). Each patient and caregiver rated the patient’s quality of life on the QOL-AD. Patient functional and cognitive status, psychological state, physical function, and behavior problems were also assessed. Reliability and validity of patient QOL-AD reports were examined across three levels of cognitive impairment. Results One hundred, fifty-five patients were able to complete the QOL-AD. Completers scored between 4 and 29 on the Mini Mental State Exam, whereas noncompleters all scored 10 or lower. Reliability for both patient and caregiver reports on the QOL-AD was good (&agr; values ranged from 0.83 to 0.90). Validity of patient and caregiver reports across cognitive levels was supported by correlation with measures of depression (r = −0.41 to −0.65), day-to-day functioning (r = −0.10 to −0.45), and pleasant events frequency (r = 0.18 to 0.51). Intraclass correlation between patient and caregiver reports was positive across all cognitive levels (r = 0.14 to 0.39). Conclusions The QOL-AD seems to be reliable and valid for individuals with MMSE scores greater than 10. Further research is needed to clarify the relationship between patient and caregiver reports of patient quality of life and to identify factors that influence quality of life throughout the progression of dementia.

Determinants of Lumbar Disc Degeneration: A Study Relating Lifetime Exposures and Magnetic Resonance Imaging Findings in Identical Twins

Study Design Retrospective cohort. Objectives To investigate the effects of lifetime exposure to commonly suspected risk factors on disc degeneration using magnetic resonance imaging, and to estimate the effects of these suspected risk factors relative to age and familial aggregation, reflecting genetic and shared environmental influences. Summary of Background Data Structural and biochemical changes associated with disc degeneration are suspected as the underlying conditions of many back-related symptoms. Little is known about the determinants of disc degeneration. Methods Based on lifetime discordance in suspected environmental risk factors for disc degeneration, 115 male identical twin pairs were selected. An indepth interview was conducted of occupational and leisure time physical loading, driving, and smoking. Disc degeneration was evaluated using observational and digital magnetic resonance imaging assessment methods. Results Heavier lifetime occupational and leisure physical loading was associated with greater disc degeneration in the upper lumbar levels (P = 0.055− 0.001), whereas sedentary work was associated with lesser degeneration (P = 0.006). These univariate associations did not reasch statistical significance in the lower lumbar region. In multivariate analyses of the upper lumbar levels, the mean job code explained 7% of the variability in observational disc degeneration scores; the addition of age explained 16%, and familial aggregation improved the model such that 77% of the variability was explained. In the lower lumbar levels, leisure time physical loading entered the multivariate model, explaining 2% of the variability. Adding age explained 9%, and familial aggregation raised the variability in disc degeneration scores explained to 43%. Conclusion The present study findings suggest that disc degeneration may be explained primarily by genetic influences and by unidentified factors, which may include complex, unpredictable interactions. The particular environmental factors studied, which have been among those most widely suspected of accelerating disc degeneration, had very modest effects.

Intragenic polymorphisms of the vitamin D receptor gene associated with intervertebral disc degeneration.

Study Design. A study in genetic epidemiology of disc degeneration, based on lifetime exposure data, findings on magnetic resonance imaging, and genotyping of intragenic markers. Objectives. To pursue the potential correlation between common allelic variations in the vitamin D receptor locus and degeneration of the intervertebral disc. Summary of Background Data. Familial aggregation has been observed in intervertebral disc degeneration, but the relative significance of the genetic component and shared environmental influences is unknown. The identification of relevant candidate genes associated with disc degeneration would specify a genetic component and increase our understanding of the etiopathogenesis of disc degeneration. Methods. From the population‐based Finnish Twin cohort, 85 pairs of male monozygotic twins were selected based on exposure to suspected risk factors for disc degeneration. Interview data were gathered on relevant lifetime exposures, and thoracic and lumbar disc degeneration was determined through quantitative and qualitative assessments of signal intensity on magnetic resonance imaging, and qualitative assessments of disc bulging and disc height narrowing. Possible associations were examined between disc degeneration measures and two polymorphisms of the coding region of the vitamin D receptor locus. Results. Two intragenic polymorphisms of the vitamin D receptor gene revealed an association with disc degeneration. Quantitatively assessed signal intensities of thoracic and lumbar (T6‐S1) discs were 12.9% worse in men with the TaqI tt genotype and 4.5% worse in men with the Tt genotype, compared with signal intensity in men with the TT genotype (age‐adjusted P = 0.003). A similar pattern was found between disc signal intensity and FokI genotypes; men with the ff and Ff genotypes had mean signal intensities that were 9.3% and 4.3% lower, respectively, than those in men with FF genotypes (age‐adjusted P = 0.006). The summary scores of qualitatively assessed signal intensity, bulging, and disc height were 4.0% and 6.9% worse in men with Ff and ff genotypes, respectively, when compared with those in men with the FF genotype (age‐adjusted P = 0.029). Conclusion. Specific vitamin D receptor alleles were associated with intervertebral disc degeneration as measured by T2‐weighted signal intensity, demonstrating for the first time the existence of genetic susceptibility to this progressive, age‐related degenerative process.

The Long-term Effects of Physical Loading and Exercise Lifestyles on Back-related Symptoms, Disability, and Spinal Pathology Among Men

Study Design Historical cohort, including selected subgroups. Objectives To understand the long-term effects of exercise on back-related outcomes, back pain, sciatica, back-related hospitalizations, pensions, and magnetic resonance imaging findings were studied among former elite athletes. Summary of Background Data Exercise and sports participation have become increasingly popular, as have recommendations of exercises for back problems, but little is known about their long-term effects. Methods Questionnaires were returned by 937 former elite athletes and 620 control subjects (83% response rate). Identification codes allowed record linkage to hospital discharge and pension registers. Magnetic resonance images were obtained of selected subgroups with contrasting physical loading patterns. Results Odds ratios for back pain were lower among athletes than among control subjects, with significant differences in endurance, sprinting and game sports, and wrestling and boxing. No differences in the occurrence of sciatica or in back-related pensions and hospitalizations were seen. When comparing lumbar magnetic resonance images of 24 runners, 26 soccer players, 19 weight lifters, and 25 shooters, disc degeneration and bulging were most common among weight lifters; soccer players had similar changes in the L4-S1 discs. No significant differences were seen in the magnetic resonance images of runners and shooters. Conclusions Maximal weight lifting was associated with greater degeneration throughout the entire lumbar spine, and soccer with degeneration in the lower lumbar region. No signs of accelerated disc degeneration were found in competitive runners. However, back pain was less common among athletes than control subjects and there were no significant differences in hospitalizations or pensions. No benefits were shown for vigorous exercise compared with lighter exercise with respect to back findings.

Nighttime Insomnia Treatment and Education for Alzheimer's Disease: A Randomized, Controlled Trial

Objectives: To evaluate whether a comprehensive sleep education program (Nighttime Insomnia Treatment and Education for Alzheimers Disease (NITE‐AD)) could improve sleep in dementia patients living at home with their family caregivers.

Characteristics of sleep disturbance in community-dwelling Alzheimer's disease patients.

This study examined the frequency, predictors, and impact of sleep problems in a population-based sample of 205 Alzheimers disease (AD) patients. Sleeping more than usual and early morning awakenings were the most common sleep problems reported but were the least disturbing behaviors for caregivers. Night-time awakenings were less common but were most disturbing to caregivers. Using logistic regression analyses, the factors most strongly asso ciated with night awakenings among patients were male gender, greater memory problems, and decreased functional status. Patient depression increased the risk for caregivers to rate patient sleep problems as more disturbing over all. Cluster analyses revealed three characteristic groups of patients who awakened caregivers: one group was inactive during the day but had few other behavior problems; one group had increased levels of fearfulness, fid geting, and occasional sadness; and the third group had multiple behavior problems, including frequent episodes of sadness, fearfulness, inactivity, fidgeting, and hallucinations. These findings indicate that the nature of sleep problems in AD is multifaceted; future research on the occurrence and treatment of sleep disturbance in dementia patients should consider the patterns of individual differences that may influence its development. (J Geriatr Psychiatry Neurol 1999; 12:53-59).

Associations between back pain history and lumbar MRI findings.

Study Design. Retrospective monozygotic twin cohort study. Objectives. Our goal was to investigate the associations between different spinal MRI findings and current, past year, and lifetime low back pain after adjusting for occupational physical loading, smoking, genetics, and early family influences. Summary of Background Data. The role of spinal pathology in back symptoms continues to be controversial. Methods. The study participants consisted of 115 monozygotic male twin pairs 35 to 69 years of age. The qualitatively assessed MRI parameters were as follows: disc height, bulging, herniations, anular tears, osteophytes, spinal stenosis, and endplate changes. Signal intensity was measured quantitatively. Results. After controlling for age, disc height was associated with all back pain variables studied and anular tears with LBP frequency and intensity during the 12 months before imaging. Both were associated with lifetime frequency of low back pain interfering with daily activities, disability, and intensity of the worst lifetime pain episode. Other MRI findings did not explain the various symptom histories. Adjusting for physical loading in the past 12 months increased the associations of anular tears and “low back pain today” and 12-month low back pain parameters. After controlling for genotype and other familial influences, the within-pair differences in disc height and anular tears accounted for 6% to 12% of the total variance in the within-pair differences of low back pain variables. Conclusion. These findings raise new questions about the underlying mechanisms of LBP. The sensitivities of the only significant MRI parameters, disc height narrowing and anular tears, are poor, and these findings alone are of limited clinical importance.

Differential item functioning analysis with ordinal logistic regression techniques. DIFdetect and difwithpar.

Introduction:We present an ordinal logistic regression model for identification of items with differential item functioning (DIF) and apply this model to a Mini-Mental State Examination (MMSE) dataset. We employ item response theory ability estimation in our models. Three nested ordinal logistic regression models are applied to each item. Model testing begins with examination of the statistical significance of the interaction term between ability and the group indicator, consistent with nonuniform DIF. Then we turn our attention to the coefficient of the ability term in models with and without the group term. If including the group term has a marked effect on that coefficient, we declare that it has uniform DIF. We examined DIF related to language of test administration in addition to self-reported race, Hispanic ethnicity, age, years of education, and sex. Methods:We used PARSCALE for IRT analyses and STATA for ordinal logistic regression approaches. We used an iterative technique for adjusting IRT ability estimates on the basis of DIF findings. Results:Five items were found to have DIF related to language. These same items also had DIF related to other covariates. Discussion:The ordinal logistic regression approach to DIF detection, when combined with IRT ability estimates, provides a reasonable alternative for DIF detection. There appear to be several items with significant DIF related to language of test administration in the MMSE. More attention needs to be paid to the specific criteria used to determine whether an item has DIF, not just the technique used to identify DIF.

Chronic pain in a large community sample of persons with multiple sclerosis.

Introduction: This study examined the prevalence, intensity, interference, and biopsychosocial correlates of pain in a large community-based sample of persons with multiple sclerosis (MS). Methods: Mail surveys were returned by 442 members of the King C ounty (WA) MS Association. Average pain intensity, pain-related activity interference, depressive symptoms and severity of MS were assessed. Results: Forty-four percent reported persistent, bothersome pain in the three months prior to completing the survey. Participants with pain reported an average pain intensity rating of 5.2 (SD =2.3) on the 0 (no pain) to 10 (pain as bad as could be) scale. Twenty-seven percent reported severe pain (score of 7-10), while 51% of those with pain rated the interference of their pain with daily activities as none to minimal. Twenty percent reported severe interference in activities as a result of pain. In multivariate modeling, MS illness severity, marital status, and self-ratings of overall health were significantly associated with pain-related interference with activities. Conclusions: A pproximately a fourth of this sample described having a chronic pain problem characterized by severe pain intensity and significant pain-related interference with activities. Disability due to pain may be more important than previously recognized for the MS population.

Development and assessment of a composite score for memory in the Alzheimer’s Disease Neuroimaging Initiative (ADNI)

We sought to develop and evaluate a composite memory score from the neuropsychological battery used in the Alzheimer’s Disease (AD) Neuroimaging Initiative (ADNI). We used modern psychometric approaches to analyze longitudinal Rey Auditory Verbal Learning Test (RAVLT, 2 versions), AD Assessment Schedule - Cognition (ADAS-Cog, 3 versions), Mini-Mental State Examination (MMSE), and Logical Memory data to develop ADNI-Mem, a composite memory score. We compared RAVLT and ADAS-Cog versions, and compared ADNI-Mem to RAVLT recall sum scores, four ADAS-Cog-derived scores, the MMSE, and the Clinical Dementia Rating Sum of Boxes. We evaluated rates of decline in normal cognition, mild cognitive impairment (MCI), and AD, ability to predict conversion from MCI to AD, strength of association with selected imaging parameters, and ability to differentiate rates of decline between participants with and without AD cerebrospinal fluid (CSF) signatures. The second version of the RAVLT was harder than the first. The ADAS-Cog versions were of similar difficulty. ADNI-Mem was slightly better at detecting change than total RAVLT recall scores. It was as good as or better than all of the other scores at predicting conversion from MCI to AD. It was associated with all our selected imaging parameters for people with MCI and AD. Participants with MCI with an AD CSF signature had somewhat more rapid decline than did those without. This paper illustrates appropriate methods for addressing the different versions of word lists, and demonstrates the additional power to be gleaned with a psychometrically sound composite memory score.