Proximal renal tubular acidosis associated with osteomalacia.

Vitamin D deficiency is relatively common among older persons and those with spinal cord injuries. We report a case of proximal renal tubular acidosis in a 44-year-old quadriplegic nursing home resident who had limited sunlight exposure. Laboratory studies showed a low level of serum bicarbonate, a normal serum anion gap, and a positive urine anion gap. There was no history of diarrhea. Serum calcium and phosphorus levels were 6.9 mg/dL and 3.7 mg/dL, respectively. Proximal renal tubular acidosis due to osteomalacia was suspected, which was confirmed by a low serum 25-hydroxycholecalciferol level (< 5 ng/mL) with an elevated serum parathyroid hormone level. Treatment with vitamin D and a calcium supplement led to normalization of laboratory values.

Factors related to driving difficulty and habits in older drivers.

OBJECTIVES: To evaluate the association between chronic medical conditions, functional, cognitive, and visual impairments and driving difficulty and habits among older drivers. DESIGN: Cross-sectional study. SETTING: Mobile County, Alabama. PARTICIPANTS: A total of 901 residents of Mobile County, Alabama aged 65 or older who possessed a driver's license in 1996. MEASUREMENTS: Information on demographic characteristics, functional limitations, chronic medical conditions, driving habits, and visual and cognitive function were collected via telephone. The three dependent variables in this study were difficulty with driving, defined as any reported difficulty in > or = 3 driving situations (e.g. at night), low annual estimated mileage, defined as driving less than 3000 miles in 1996, and low number of days ( < or = 3) driven per week. RESULTS: A history of falls, kidney disease or stroke was associated with difficulty driving. Older drivers with a history of kidney disease were more likely to report a low annual mileage than subjects without kidney disease. Low annual mileage was also associated with cognitive impairment. In general, older drivers with a functional impairment were more likely to drive less than 4 days per week. Older drivers with a history of cataracts or high blood pressure were more likely to report a low number of days driven per week, while subjects with visual impairment were at increased risk of experiencing difficulty driving as well as low number of days driven per week. CONCLUSIONS: The results underscore the need to further understand the factors negatively affecting driving independence and mobility in older drivers, as well as the importance of improved communication between older adults and health care professionals regarding driving.

Mobility impairments in crash-involved older drivers.

OBJECTIVE: To evaluate potential associations of impairments in physical function with motor vehicle crash involvement in older drivers. METHODS: Case participants were randomly selected residents of Mobile County, Alabama, greater or less than 65 years old who had sustained an at-fault motor vehicle crash in 1996. Similarly selected crash-free controls were frequency matched to cases on gender and age. Self-report data on demographic variables, medical conditions, medications, driving exposure, and function were collected by telephone interviewers. RESULTS: Relative to crash-free subjects, crash-involved drivers were significantly more likely to report difficulty walking one fourth mile and moving outdoors. Marginally significant associations were observed for trouble carrying a heavy object 100 yards and for the occurrence of falls in the prior year. Increasing numbers of functional limitations were directly related to the odds of crash involvement. DISCUSSION: In comparison to crash-free controls, crash-involved older drivers are more likely to report other mobility-related impairments, possibly including falls.

Relations among chronic medical conditions, medications, and automobile crashes in the elderly: a population-based case-control study.

Older drivers have elevated crash rates and are more likely to be injured or die if they have a crash. Medical conditions and medications have been hypothesized as determinants of crash involvement. This population-based case-control study sought to identify medical conditions and medications associated with risk of at-fault crashes among older drivers. A total of 901 drivers aged 65 years and older were selected in 1996 from Alabama Department of Public Safety driving records: 244 at-fault drivers involved in crashes; 182 not at-fault drivers involved in crashes; and 475 drivers not involved in crashes were enrolled. Information on demographic factors, chronic medical conditions, medications, driving habits, visual function, and cognitive status was collected. Older drivers with heart disease (odds ratio (OR) = 1.5, 95% confidence interval (CI): 1.0, 2.2) or stroke (OR = 1.9, 95% CI: 0.9, 3.9) were more likely to be involved in at-fault automobile crashes. Arthritis was also associated with an increased risk among females (OR =1.8, 95% CI: 1.1, 2.9). Use of nonsteroidal antiinflammatory drugs (OR = 1.7, 95% CI 1.0, 2.6), angiotensin converting enzyme inhibitors (OR = 1.6, 95 CI: 1.0, 2.7), and anticoagulants (OR = 2.6, 95% CI: 1.0, 73) was associated with an increased risk of at-fault involvement in crashes. Benzodiazepine use (OR = 5.2, 95% CI: 0.9, 30.0) was also associated with an increased risk. Calcium channel blockers (OR = 0.5, 95% CI: 0.2, 0.9) and vasodilators (OR = 0.3, 95% CI: 0.1, 1.0) were associated with a reduced risk of crash involvement. The identification of medical conditions and medications associated with risk of crashes is important for enhancing the safety and mobility of older drivers.

Exploratory study of incident vehicle crashes among older drivers.

BACKGROUND: As the number of older adult drivers increases, distinguishing safe from unsafe older adult drivers will become an increasing public health concern. We report on the medical and functional factors associated with vehicle crashes in a cohort of Alabama drivers, 55 years old and older. METHODS: This prospective study involved 174 older adults, on whom demographic, medical, functional, and physical performance data were collected in 1991. Subjects were then followed through 1996 for incident vehicle crashes. RESULTS: Sixty-one subjects experienced between one and four police-reported vehicle crashes during the study period. Following adjustment for age, race, days driven per week, and gender, Cox proportional-hazards models showed the following variables to be associated with crash involvement: reported difficulty with yardwork or light housework (relative risk [RR] = 2.1; 95% confidence interval [CI] 1.1, 4.0; p = .02), or opening ajar (RR = 3. 1; 95% CI 1.4, 6.7; p = .004); at least one crash before 1991 (RR = 2.1; 95% CI 1.2, 3.7; p = .008); using hypnotic medication (RR = 2.9; 95% CI 1.3, 6.6; p = .01); self-reported stroke or transient ischemic attack (RR = 2.7; 95% CI 1.1, 6.6; p = .03); scoring within the depressed range on the Geriatric Depression Scale (RR = 2.5; 95% CI 1.1, 6.0; p = .03), and failing the useful field-of-view test (RR = 1.9; 95% CI 1.0, 3.5; p = .05). CONCLUSIONS: Variables related to function, medication use, affect, neurological disease, and visuocognitive skills were associated with vehicle crash involvement in this cohort. Our findings suggest that multifactorial assessments are warranted to identify at-risk older drivers.

Diabetes and automobile crashes in the elderly. A population-based case-control study.

OBJECTIVE: The aim of this study was to estimate the association between diabetes and its complications and at-fault automobile crashes among older drivers. RESEARCH DESIGN AND METHODS: This was a population-based case-control study. Case subjects were drivers aged > or = 65 years who had been involved in a crash during 1996 in which they were at fault. Two control groups were selected: 1) crash-involved not-at-fault subjects and 2) non-crash-involved subjects. Telephone interviewers collected information on demographic characteristics, driving habits, diabetes sequelae and treatment, other chronic medical conditions, and visual function. RESULTS: Overall, there was no association between diabetes and at-fault crash involvement. The adjusted odds ratio (OR) for diabetes was 1.1 (CI 0.7-1.9) when case subjects were compared with either control group. However, the adjusted OR for diabetes was 2.5 (0.9-7.2) among subjects who had been involved in a crash in the 4 years preceding 1996, while it was only 0.9 (0.5-1.7) among those who had not. There was no evidence of an association between treatment modalities and at-fault crash involvement. Case subjects were, although not significantly (P = 0.25), more likely (OR 2.4) to report neuropathy compared with both control groups, and retinopathy was not associated with increased crash risk. CONCLUSIONS: This study provides no evidence that older drivers with diabetes are at increased risk for automobile crashes. There remains the possibility that those with diabetes who have more severe disease or have had multiple crashes are at increased risk.

A preliminary assessment of the medical and functional factors associated with vehicle crashes by older adults.

OBJECTIVES: To examine associations between medical and functional variables and at-fault car crashes in a cohort of older drivers. DESIGN: A case-control study. SETTING: A tertiary care medical center. PARTICIPANTS: Older drivers (ages 55-90 years) residing in Jefferson County, Alabama (n = 174). Cases were drivers who had at least one at-fault crash in the previous 6 years; controls were crash-free during the same period. MEASUREMENTS: Self-reported medical conditions, reported and observed functional measures, and urinary drug screens. The occurrence of one or more at-fault car crashes in the 6 years preceding the 1991 assessment date represented the outcome measure. RESULTS: Ninety-nine older drivers experienced between one and seven at-fault vehicle crashes during the period 1985 through 1991, whereas 75 drivers did not. Logistic regression models indicated that the following variables were independently associated with crash involvement: A 40% or greater reduction in the useful field of view (OR = 6.1; 95% CI, 2.9 to 12.7; P < 0.001), black race (OR = 6.6; 95% CI, 1.7 to 26.2; P = .007), a history of falling in the previous 2 years (OR = 2.6; CI, 1.1 to 6.1; P = .025), and not taking a beta-blocking drug (OR = 4.3; CI, 1.2 to 15.0; P = .023). CONCLUSIONS: Functional assessments, such as a comprehensive test of visual processing, a falls history, and a review of current medications may be of greater relevance than specific medical conditions in the identification of older at-risk drivers. If prospective studies determine that falling and crashing share risk factors, a unified approach to the prevention of these mobility disorders could result. The finding of an independent association of black race with at-fault crashing is in need of further clarification because of the low representation of black drivers in this sample.

Acute gastroenteritis in three community-based nursing homes.

BACKGROUND: Acute gastroenteritis is a cause of considerable morbidity and mortality in the elderly population. A prospective assessment of acute diarrhea in three community-based long-stay homes is described. METHODS: A cohort study of acute gastroenteritis was performed in three community-based nursing homes, involving 572 residents over an 8-month period. Diarrhea cases were enrolled on the basis of the acute onset of loose stools of > or = 24 hours, as well as one of the following: a rectal temperature of > or = 100 degrees F, dehydration, positive occult blood, > or = 48 hours duration, or as a part of any outbreak. Stool cultures for Clostridium difficile were performed on all NH 1 patients. RESULTS: Fifty-three gastroenteritis cases were ascertained, consistent with incidence rates of 14.6, 36.4, and 6.7 cases/100 patient years in NH 1, NH 2, and NH 3, respectively. Requiring a Foley catheter (OR = 2.57; 95% CI, 0.93, 7.09) increased diarrhea risk. Six Clostridium difficile enteritis cases and an episode attributable to Aeromonas/Pleisomonas species were diagnosed. One C. difficile diarrhea case was imported from hospital to NH 1. Ten of 12 fecal excretors resided in close geographic clusters in NH 1, where a majority of the latter were mobile and incontinent of stool. CONCLUSIONS: Acute gastroenteritis was a common disease in the study nursing homes, for which specific risk factors were identified. A predominant role for Clostridium difficile in the taxonomy of nursing home diarrhea was suggested.

The role of age in susceptibility to pneumococcal infections.

Whether or not age by itself increases susceptibility to pneumococcal infections separate from the effects of chronic disease is controversial. To address this issue, data collected for a retrospective cohort study of pneumococcal infections among 63 middle-aged and older veterans and 126 uninfected controls were reanalysed. Univariate analysis suggested a linear increase in risk with increasing age for patients 50 years old and older (p = 0.03). Subjects over age 80 years seemed to be at particularly high risk when compared with patients under 50 (odds ratio = 4.3, p less than 0.03). The odds of pneumococcal infection increased by an estimated factor of 1.33 (95% confidence interval = 1.03, 1.71) for each 10-year increase in age. Controlling for other risk factors did not appreciably change the point estimate of the age effect, but statistical significance was lost. This result however suggests that age has an independent association with the risk of pneumococcal infections. The potential impact of this finding on public policy urges that the association of age with the risk of pneumococcal disease be re-examined in a study of sufficient sample size to resolve the issue.

Amantadine-related adverse reactions among African-American elderly nursing home residents.

To identify factors associated with the development of adverse reactions to amantadine prophylaxis for influenza in a predominantly African-American nursing home population, we retrospectively reviewed the records of 100 residents who did and 45 who did not receive amantadine. During the 4 weeks of amantadine treatment, three independent observers rated all new symptoms as either related or unrelated to amantadine. Two types of comparison were made. Among patients receiving amantadine, those who did or did not develop new symptoms believed to be related to amantadine were compared by age, underlying diagnoses, type and number of medications, and renal function. Similar comparisons were made between patients who did and those who did not receive amantadine. The 100 residents who received amantadine prophylaxis had significantly more nonspecific symptoms than the 45 who did not receive amantadine. Otherwise, the two groups were comparable with regard to age, renal function, number of diagnoses, and medications. Of the 100 residents given amantadine, 16% were judged to experience amantadine-related adverse reactions. Those developing amantadine-related symptoms were significantly more likely to have nonspecific symptoms and to use psychotropic medications.

Bacterial pneumonia in the elderly.

Bacterial pneumonia is among the most frequent diagnoses that bring elderly patients to the Emergency Department. The morbidity and mortality subsequent to these infections is very high among these individuals, and presenting symptoms and signs may be subtle. Gram-negative bacilli, H. influenzae, and mixed organisms more commonly cause lower respiratory tract infections in this population. The diagnosis and management of nursing home and community-acquired pneumonias are reviewed, as are important preventative strategies.

Integrating residency training in geriatrics into existing outpatient curricula.

In recent years, the need for increasing the geriatrics component of residency training has been repeatedly addressed; however, there are still many programs that have been unable to meet this need. While alternative sites, such as geriatric evaluation units and nursing homes, may be the ideal sites to teach some aspects of geriatrics, this article argues that the ambulatory care program, required in all residency programs, is the appropriate setting for teaching many of the core skills needed to care for most older adults. Teaching geriatrics in the ambulatory setting, which eliminates the strategic and financial obstacles of developing non-hospital-based sites, can be accomplished with relatively modest additional resources. This article describes the methods used to integrate geriatrics into the ambulatory care component of one internal medicine residency program and the necessary faculty resources as well as the documentation, via chart audit, of the interns' compliance with recommended practice patterns in five categories. With the exception of vaccination status, interns documented 18% or less of possible pieces of information for their patients. While this assessment showed statistically significant improvement in interns' care of older patients after the program intervention, the overall level of performance was still low, underscoring the need for the integration of geriatrics principles in the ambulatory curriculum.

The clinical effectiveness of pneumococcal vaccine in the elderly.

The effectiveness of pneumococcal vaccine in the immunocompetent elderly remains controversial. We report the results of a multicenter, case-control study of 244 controls and 122 patients, aged 55 years and older, hospitalized during a 5-year period with pneumococcal bacteremia, meningitis, or other bacteriologically confirmed pneumococcal infection. Two controls per patient were matched on the basis of admission date, hospital records, and underlying diseases. All subjects were selected without knowledge of immunization status with pneumococcal vaccine, and were excluded if there was evidence for immunosuppression due to disease or iatrogenic causes. The clinical effectiveness of the vaccine was calculated to be 70% (95% confidence intervals [CI], 37% to 86%) in this population, based on a Mantel-Haenszel point estimate of the odds ratio of 0.30 (95% CI, 0.14% to 0.63%; P less than 0.005). The clinical effectiveness of pneumococcal vaccine in preventing pneumococcal infection in the immunocompetent elderly approximates the vaccine's effectiveness in the general immunocompetent population.

Bioavailability of glipizide and its effect on blood glucose and insulin levels in patients with non-insulin-dependent diabetes.

The bioavailability of glipizide, plasma glucose, and insulin levels were measured in seven patients with non-insulin-dependent diabetes mellitus. Glucose and insulin response to three standard meals was measured at 11 identical time points on the day of placebo administration and on the first and 15th day of glipizide administration (mean dose of 8.7 mg glipizide orally per day). The bioavailability profile of glipizide was highly consistent between day 1 and day 15 of administration. On both days, the drug peaked within 1.2-1.8 h and displayed a plasma half-life of between 2.5 and 3.2 h. While insulin levels were significantly (P less than 0.05) increased at 4 of 11 time points of day 1, significantly elevated insulin levels were found at one time point on day 15 of glipizide administration. Insulin levels were found to be increased only in the presence of plasma drug concentrations of 200 ng/ml or greater. The hypoglycemic effect of the drug was significantly greater on day 15 than on day 1 of administration, and a significant hypoglycemic effect was noted even when drug levels were undetectable in plasma.

Acetaldehyde adducts with hemoglobin.

Clinical studies on the minor hemoglobins (hemoglobin A1a-c) have suggested that a novel adduct may form in people abusing alcohol. Such patients were found to have an elevated concentration of minor hemoglobins, but normal or subnormal amounts of glycosylated hemoglobin (hemoglobin A1c) as determined by radioimmunoassay, Acetaldehyde, a reactive metabolite of ethanol, was postulated to form adducts with hemoglobin A that change its chromatographic properties. At physiological concentrations, acetaldehyde was found to form adducts with hemoglobin that were stable to extensive dialysis for several days. The amount of hemoglobin adducts formed were a function of the concentration and number of exposures to acetaldehyde. The reaction of acetaldehyde with hemoglobin A produced chromatographic variants, some of which migrated in the hemoglobin A1a-c region. Analysis of stable acetaldehyde-hemoglobin adducts demonstrated that valine, lysine, and tyrosine residues of globin were sites of reaction. The acetaldehyde-modified amino acid residues appear to exist in interconvertible conformations, only one of which is reducible by sodium borohydride. The amount of these adducts was found to be significantly elevated in hemoglobin from alcoholics as compared with normal volunteers.