The effects of demographics, functioning, and perceptions on the relationship between self-reported and objective measures of driving exposure and patterns among older adults.

The exploratory study reported here was intended to examine: how strongly subjectively reported driving avoidance behaviors (commonly referred to as self-regulation) and exposure were related to their objectively measured counterparts and whether it depended on the specific behavior; the extent to which gender and age play a role in the association between subjectively reported driving avoidance behaviors and exposure and their objectively measured counterparts; and the extent to which demographics, health and functioning, driving-related perceptions, and cognition influence the association between subjective and objective driving avoidance behaviors overall. The study used data from the Longitudinal Research on Aging Drivers (LongROAD) study, a multisite, prospective cohort study designed to generate empirical data for understanding the role of medical, behavioral, environmental, and technological factors in driving safety during the process of aging. Objective driving measures were derived from GPS/datalogger data from 2131 LongROAD participants' vehicles. The corresponding subjective measures came from a comprehensive questionnaire administered to participants at baseline that asked them to report on their driving exposure, patterns, and other aspects of driving. Several other variables used in the analyses came from the comprehensive questionnaire and an inperson clinical assessment administered to participants at baseline. A series of simple linear and logistic models were fitted to examine the relationship between the subjective and objective driving measures of interest, and a multivariable analysis was conducted to examine the potential role of selected factors in the relationship between objective and subjective driving avoidance behaviors. Results of the models are presented and overall findings are discussed within the context of the existing research literature.

Graduated driver licensing in Michigan: early impact on motor vehicle crashes among 16-year-old drivers.

CONTEXT: Graduated driver licensing (GDL) programs are being adopted in many states to address the high rate of motor vehicle fatalities among teens by requiring teenaged drivers to gain experience and maturity under conditions of relatively low crash risk before gaining full driving privileges. OBJECTIVE: To evaluate the early impact of Michigan's GDL program on traffic crashes among 16-year-old drivers. DESIGN, SETTING, AND SUBJECTS: Analysis of Michigan motor vehicle crash data from 1996 (before GDL program implementation) vs 1998 and 1999 (after GDL program implementation) for 16-year-olds, adjusting for trends among persons 25 years or older. INTERVENTION: Michigan's GDL program, instituted April 1, 1997, for teens younger than 18 years entering the driver license system, includes 3 licensure levels, each with driving restrictions and requirements to progress to the next level. Requirements include extended, supervised practice in the learning level, 2-phase driver education, and night driving restrictions in the intermediate level. MAIN OUTCOME MEASURES: Rates in 1996 vs 1998 and 1999 for all police-reported crashes; for fatal injury, nonfatal injury, and fatal/nonfatal injury combined crashes; for day, evening, and night crashes; for single-vehicle and multivehicle crashes; and for alcohol-related crashes. RESULTS: Overall, the rate of 16-year-old drivers (per 1000 population) involved in crashes declined from 154 in 1996 to 111 in 1999 (relative risk [RR], 0.72; 95% confidence interval [CI], 0.71-0.73). After adjusting for populationwide trends, the overall crash risk for 16-year-olds was significantly reduced in 1999 from 1996 by 25% (adjusted RR, 0.75; 95% CI, 0.74-0.77). There were also significant reductions for nonfatal injury and combined fatal and nonfatal crashes; for day, evening, and night crashes; and for single-vehicle and multivehicle crashes. Fatal crashes declined from 1996 to 1999, but not significantly (RR, 0.74; 95% CI, 0.49-1.14), and alcohol-related crashes continued at a low rate (RR, 1.01; 95% CI, 0.80-1.29). CONCLUSIONS: Analysis of the first 2 full calendar years following Michigan's GDL program implementation indicates substantial crash reductions among 16-year-olds. Future research is necessary to determine if these reductions are maintained and if other jurisdictions achieve similar results.

Juvenile rheumatoid arthritis of the knee: evaluation with contrast-enhanced color Doppler ultrasound.

BACKGROUND: Contrast-enhanced color Doppler ultrasonography is a non-radiation-bearing tool that can be of value for assessment of inflammatory and vascular synovial changes in juvenile rheumatoid arthritis (JRA). OBJECTIVES: To evaluate the effect of contrast-enhanced color Doppler ultrasound (US) in the evaluation of synovial changes in the knees of children with JRA. MATERIALS AND METHODS: Sagittal color Doppler sonograms of 31 knees in 22 patients with JRA and of 10 knees in 5 control subjects were obtained before (at baseline) and after (at peak contrast phase) intravenous injection of SHU 508. Images were assessed for overall mean pixel intensity within the synovial tissue and for peak enhancement ratios [[(mean pixel intensity values at maximum contrast enhancement-unenhanced mean pixel intensity values)/unenhanced mean pixel intensity values] x 100]. The joints were classified into three groups by clinical/laboratory criteria: group A (active disease in the knee), n = 9; group B (quiescent disease with serum chemistry levels of active disease), n = 12 and group C (remission disease), n = 10. RESULTS: Mean color pixel intensity values were markedly increased by the use of US contrast agents in groups A (P = 0.004) and B (P = 0.0001), did not reach statistical significance in group C (P = 0.06) and remained essentially unchanged in the control group (P = 0.25). Enhancement ratios for the three groups of JRA patients were not different (P = 0.38) (mean +/- SD, 720% +/- 402 for group A, 731% +/- 703 for group B and 314% +/- 263 for group C). CONCLUSION: Contrast-enhanced color Doppler imaging holds promise for the detection of active synovial inflammatory disease in subclinical cases of JRA, thereby allowing earlier treatment and improved clinical outcome.

Doppler mapping of direct carotid-cavernous fistulae (DCCF).

The aims of this study were to establish Doppler criteria for identifying direct carotid-cavernous fistulae (DCCF), as well as the level of agreement between results obtained by Doppler mapping vs. angiography. Doppler mapping and angiography were used to assess the direction of flow in the superior ophthalmic veins and the resistivity index in the internal carotid arteries of 30 patients with DCCF. Both methods independently demonstrated reverse flow in superior ophthalmic vein ipsilateral to the DCCF in 22 patients and normal flow in another four. The mean resistivity index for internal carotid arteries with ipsilateral DCCF was significantly reduced (p = 0.0001) compared with that for contralateral internal carotid arteries without DCCF. A resistivity index value of 0.495 offered a sensitivity and specificity of 86.6% in diagnosing ipsilateral DCCF. These findings suggest that a resistivity index < 0.495 in the ipsilateral internal carotid artery, with or without reverse flow in the superior ophthalmic vein, is associated with a reasonable probability of diagnosing DCCF.

Trends in driver and front-right passenger safety belt use in Michigan: 1984-1998.

As part of Michigan's effort to track trends in safety belt use within the state over time, the University of Michigan Transportation Research Institute conducted 20 statewide surveys of safety belt use between 1984 and 1998. Results indicate that Michigan safety belt use trends for drivers and front-right passengers are similar to other statewide and national trends. Belt use in Michigan increased dramatically immediately after the state implemented its mandatory belt use law (secondary enforcement) followed by a smaller decline that leveled off at a rate more than 20 percentage points higher than before the law. Belt use was consistently higher among drivers than front-right passengers, older than younger front-outboard occupants, females than males, and front-outboard occupants exiting freeways than those stopped at local intersections. Examination of belt use trends in Michigan provides useful information for continued efforts to increase belt use in our state and for all states interested in meeting national goals for safety belt use for the year 2000 and beyond.

Colour Doppler ultrasound: a new index improves the diagnosis of renal artery stenosis.

The description of a new index, the renal-segmental ratio (RSR), and the comparison of its performance with other conventional Doppler parameters for the detection of renal artery stenosis (RAS). A total of 96 renal units were studied with angiography and colour Doppler ultrasound (US) independently. The Doppler parameters applied were: 1. renal artery peak systolic velocity (RE-PSV), 2. renal-aortic ratio (RAR), 3. early systolic acceleration (ESA), and 4. renal-segmental ratio (RSR). The angiographic study was used as the "gold standard" for the identification of > or = 50% RAS. The results indicate that RSR (sensitivity: 93.33%, specificity: 89.47%) and RE-PSV (sensitivity: 83.33%, specificity: 89.47%) were the best criteria for RAS diagnosis (p values <0.05). The results show that colour Doppler US is a reliable diagnostic modality for RAS diagnosis. The new index (RSR) improves the effectiveness of the method.

Estimating blood alcohol content from a national telephone survey.

One of the best methods for estimating blood alcohol content (BAC) in the driving population is through roadside breathtesting surveys that measure directly the BAC levels of drivers. However, there are barriers to conducting roadside breathtesting surveys in some states in the US. An alternative method for assessing BAC in the driving population may be to estimate BAC from self-reports of alcohol-involved driving collected via telephone surveys. This paper documents the results of estimating BAC in the driving population based on self-reported drinking, sex, and weight from a 1997 national telephone survey of US adult residents. These results are then discussed in light of findings from roadside surveys.

Three-dimensional (3D) contrast-enhanced power Doppler imaging in Legg-Calvé-Perthes disease.

BACKGROUND: The revascularization process of the femoral head in Legg-Calvé-Perthes disease has not been well studied on Doppler images. We incorporated two relatively new developments in ultrasound: 3D power Doppler imaging combined with the use of contrast agents. PATIENTS AND METHODS: We studied two children with unilateral Legg-Calvé-Perthes disease through anterior-sagittal approaches with pre- and post-contrast power Doppler images, acquired in 2D and 3D planes. RESULTS: In one patient, intraosseous vessels were detected only in the pathological femoral head both pre- and post-contrast administration. In the other, no flow was identifiable without the use of contrasts. CONCLUSION: The use of ultrasound contrast agents combined with 3D imaging modalities offers new alternative methods for visualization of intraosseous vascularity.

The effects of carotid endarterectomy on the retrobulbar circulation of patients with severe occlusive carotid artery disease. An investigation by color Doppler imaging.

OBJECTIVE: To analyze the effects of carotid endarterectomy on the retrobulbar circulation of patients with severe occlusive carotid artery disease (OCAD) by means of color Doppler imaging (CDI). DESIGN: Prospective. PARTICIPANTS: A total of 17 consecutive patients with severe OCAD and neurologic symptoms (with a history of transitory ischemic attack or cerebral vascular accident) participated. INTERVENTION: All 17 patients underwent carotid endarterectomy. The CDI of both orbits was performed by one masked investigator before surgery and at 1 week and 1 month after surgery. MAIN OUTCOME MEASURES: Peak systolic velocity, end diastolic velocity, and resistive index of the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. The authors compared the hemodynamic parameters at all intervals. RESULTS: Peak systolic and end diastolic velocities in the ophthalmic, central retinal, and temporal short posterior ciliary arteries increased significantly 1 week and 1 month after carotid endarterectomy (P < 0.05). After surgery, the resistive indices in the central retinal and temporal short posterior ciliary arteries decreased significantly at both intervals (P < 0.05). The six patients who had reversed ophthalmic artery flow before surgery showed forward ophthalmic artery flow after carotid endarterectomy. The contralateral orbits showed no significant hemodynamic change after endarterectomy (P < 0.05). CONCLUSIONS: Hemodynamic changes in patients with severe OCAD undergoing carotid endarterectomy suggest improvement in the ipsilateral retrobulbar blood flow.

Cardiac effects of persistent hemodialysis arteriovenous access in recipients of renal allograft.

In hemodialysis patients, large arteriovenous (AV) fistulas for vascular access may cause ventricular hypertrophy and high-output cardiac failure. The long-term cardiac consequences of functional AV fistulas in renal transplant patients are unclear. A precise knowledge of these consequences is important to decide if and when such fistulas should be closed in successfully transplanted patients. In this retrospective study including 61 stable renal transplant patients with adequate renal function (serum creatinine <2.0 mg/100 ml), echocardiography was performed in 39 patients with a functional AV fistula (group 1) and in 22 whose fistulas had been closed, for esthetic reasons, within 2 months postoperatively (group 2). The volume flow of the fistulas, measured in 22 randomly selected individuals of group 1, was 900 +/- 350 ml/min (range 500-1,600). Patients of group 1 were older (40 +/- 12 vs. 33 +/- 12 years, p < 0.05), had longer duration of the fistula (62 +/- 31 vs. 36 +/- 30 months, p < 0.05), higher body mass index (24 +/- 4 vs. 22 +/- 3 kg/m2, p < 0.05), systolic (154 +/- 24 vs. 138 +/- 18 mm Hg, p < 0.05) and diastolic (96 +/- 12 vs. 89 +/- 11 mm Hg, p < 0.05) blood pressure and increased left ventricular (LV) end-diastolic dimension (53 +/- 5 vs. 49 +/- 5 mm, p < 0.01). LV mass, cardiac index, ejection fraction and the proportion of patients with LV hypertrophy were comparable in the two groups. LV end-diastolic dimension was positively and independently influenced only by the presence of the AV fistula (p < 0.01) after adjusting for age, duration of the fistula, body mass index, systolic and diastolic blood pressure and the nature of the antihypertensive drugs used. In conclusion, the persistence of large, high-flow AV fistulas for prolonged periods of time had little impact on cardiac morphology and function of stable renal transplant patients with adequate renal function. The data do not support routine closure of these fistulas in all renal transplant patients.

Duplex sonographic evaluation of the sapheno-femoral venous junction in patients with recurrent varicose veins after surgical treatment.

PURPOSE: We used duplex sonography in patients with recurrent varicose veins after surgical treatment to detect any residual stump of the great saphenous vein at the sapheno-femoral venous junction, and we compared these sonographic findings with surgical findings as the "gold standard." METHODS: We prospectively studied 65 patients (54 women and 11 men) who had recurrent varicose veins 1-30 years (mean, 11 years) after surgical exploration of the groin and ligature of the great saphenous vein at its junction with the femoral vein. Duplex scans were performed in all patients before surgical reexploration. Sonographic findings were compared with surgical findings. RESULTS: Duplex scanning revealed a residual stump in 47 patients (72%) and no stump in 15 patients (23%). Thirty-five (74%) of the 47 cases with a residual stump had reflux on duplex scans, and the remaining 12 cases (26%) showed no reflux. Findings in all 62 of these cases were confirmed by surgery. In only 3 patients (5%) did duplex scans fail to show a residual stump when surgery revealed a small residual stump without reflux. CONCLUSIONS: Duplex scanning is the noninvasive diagnostic technique of choice to detect any residual stump of the great saphenous vein and to diagnose valve failure at the sapheno-femoral venous junction in patients with recurrent varicose veins.

Diagnosis of limbs and neck arterial trauma using duplex ultrasonography.

OBJECTIVE: To evaluate duplex ultrasonography for diagnosis of arterial trauma in limbs and neck. METHOD: Fifty-one wounds in 47 patients, with indication for arteriography, were prospectively studied and grouped according to the presence (PCS group: 21 wounds, 41.2%) or absence (ACS group: 30 wounds, 58.8%) of clinical signs of arterial injury. All underwent duplex ultrasonography and arteriography. RESULTS: Arteriography disclosed arterial injury in 21 wounds, of which 19 were visualized by duplex ultrasonography. In the other 30 wounds neither methods disclosed any arterial injury. The sensitivity of duplex ultrasonography was 90.5%, the specificity was 100% and the accuracy was 96.1%. In PCS group duplex ultrasonography showed 14 injuries (93.3%) and one false-negative result, and in ACS group, five injuries (83.3%) and one false-negative result in the ACS group. CONCLUSIONS: Duplex ultrasonography reproduces the results of arteriography as a non-invasive diagnostic method in trauma of the limbs and neck.

Collateral blood supply through the ophthalmic artery: a steal phenomenon analyzed by color Doppler imaging.

OBJECTIVE: This study aimed to evaluate the retrobulbar circulatory effects of reversed ophthalmic artery flow (ROAF) on the ophthalmic artery branches by means of color Doppler imaging. DESIGN: The design was a case-controlled study. PARTICIPANTS: Among 56 consecutive patients with severe (>70% stenosis) occlusive carotid artery disease, 15 patients (26.8%) with ROAF were identified. The control group consisted of 15 patients with similar degrees of carotid artery stenosis and forward ophthalmic artery flow. INTERVENTION: Arteriography and measurement of the retrobulbar hemodynamic parameters with color Doppler imaging were performed. MAIN OUTCOME MEASURES: Blood flow velocities and resistive index in the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. RESULTS: Arteriography confirmed the diagnosis of ROAF in all 15 patients. There was no patient with ROAF diagnosed by arteriography and not diagnosed by color Doppler imaging. The frequency of bilateral severe occlusive carotid artery disease was significantly higher in the ROAF group (40%) compared to the control group (6.6%) (P = 0.04). Patients with ROAF showed significantly reduced vascular resistance in the ophthalmic artery (P = 0.03), higher vascular resistance, and lower blood flow velocities in the central retinal and temporal short posterior ciliary arteries (P < 0.05). CONCLUSION: This study suggests that patients with ROAF show a steal phenomenon, characterized by a shunt to the low-resistance intracranial circuit and reduction of retrobulbar blood flow.

Clinical findings and hemodynamic changes associated with severe occlusive carotid artery disease.

OBJECTIVE: The purpose of the study was to evaluate the ophthalmologic findings and to analyze the retrobulbar hemodynamics of patients with severe (greater than 70% stenosis) occlusive carotid artery disease (OCAD) by means of color Doppler imaging (CDI). DESIGN: A case-controlled study. PARTICIPANTS: Fifty-six consecutive patients with severe OCAD and an age- and sex-matched control group consisting of 56 healthy patients without OCAD were studied. INTERVENTION: All 112 patients underwent a complete ophthalmologic examination. Color Doppler imaging of both orbits was performed by one masked investigator. MAIN OUTCOME MEASURES: Peak systolic velocity, end diastolic velocity, and the resistive index of the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. The authors compared the hemodynamic parameters measured in patients with severe OCAD with those obtained in the control group. The hemodynamic parameters of patients with asymmetric OCAD (stenosis > 70% in one internal carotid artery and stenosis < 50% in the contralateral artery) were also compared. In an attempt to determine risk factors associated with the ocular ischemic syndrome (OIS), the authors compared patients with severe OCAD and OIS with patients with severe OCAD without OIS. RESULTS: Peak systolic and end diastolic velocities in the ophthalmic, central retinal, and temporal short posterior ciliary arteries were significantly lower in patients with severe OCAD (P < 0.01). The mean resistive indices in the central retinal and temporal short posterior ciliary arteries were higher in the group with severe OCAD (P < 0.01). Similar results were obtained in the analysis of 25 patients with asymmetric carotid stenosis. Younger age (P = 0.012), severe bilateral OCAD (P = 0.01), high-grade carotid stenosis (P = 0.013), and reversed ophthalmic artery flow (P = 0.038) were significant risk factors for OIS. CONCLUSIONS: Patients with severe OCAD show hemodynamic changes that suggest reduced retrobulbar blood flow. Patients with severe bilateral OCAD, high-grade carotid stenosis, and reversed ophthalmic artery flow may have a greater risk of developing OIS.

Diagnosing and monitoring carotid cavernous fistulas with color Doppler imaging.

Color Doppler imaging allows simultaneous bidimensional imaging and Doppler evaluation of blood flow in orbital vessels. We report 4 cases in which color Doppler imaging was used to diagnose and monitor carotid cavernous fistulas. In all cases, color Doppler imaging demonstrated dilated, arterialized superior ophthalmic veins; these findings were confirmed by angiography. Two patients underwent embolization with complete regression of the clinical findings. After embolization, color Doppler imaging revealed normal, laminar flow in the superior ophthalmic vein. This noninvasive technique represents a safe and fast method that is useful in the diagnosis and post-treatment follow-up of carotid cavernous fistulas.

Ophthalmic artery aneurysms: an investigation by duplex scan.

With the objective of analyzing the postaneurysmal peak systolic velocity (PSV) in ophthalmic arteries, duplex scanning was analyzed in 28 carotid-ophthalmic artery segments after exclusion of ipsilateral carotid stenosis. For comparison, the angiographic study of the extracranial and intracranial carotid system was utilized as the "gold standard." A subgroup of 7 subjects with 8 ophthalmic arteries with aneurysms identified where the artery leaves the internal carotid artery presented with PSVs significantly reduced (mean PSVs 17.95 +/- 7.99 cm/s) compared to the mean PSVs in the healthy group (27.95 +/- 5.54 cm/s) (p = 0.006). A PSV of less than 19 cm/s offered a sensitivity of 80% and a specificity of 100% in diagnosing ophthalmic artery aneurysms. We conclude that duplex scan is diagnostically useful in the identification of patients with ophthalmic artery aneurysms when severe ipsilateral carotid stenosis is excluded.

Developing policies for automated speed enforcement: a survey of Michigan opinions.

This paper describes select results of a pilot test of automated speed enforcement devices (ASEDs) in Michigan. A mail response survey of drivers (1,209 respondents) showed the general public favors use of ASEDs in select situations, particularly in school zones, in areas where traffic enforcement is dangerous for police, for heavy trucks, and in construction zones. The survey also showed opposition to ASED use on freeways, on bridges, and on "all roads." In general, observed speeders and persons who reported having multiple citations in the previous two years were in greater opposition to the use of ASEDs than the general population.

Prevalência de aneurisma intra-abdominal em idosos / Prevalence of intraabdominal aneurysm in elderly patients

OBJETIVOS. Estudo em idosos de freqüência de aneurisma em artérias do abdome(AAA) e do diâmetro máximo da aorta abaixo das artérias renais naqueles sem dilataçäo arterial. MATERIAL E MÉTODOS. Foram estudados 411 indivíduos, 218 mulheres e 193 homens, com média de idade de 74,4 anos. Foram feitos o exame físico de abdome (EF) e a ultrasonografia de abdome (US), sendo este considerado o "padräo-ouro" de referência. Para a aorta, foi considerado aneurisma o diâmetro de artéria superior a 30 mm e, para as artérias ilíacas, o diâmetro máximo superior a 15mm. RESULTADOS. A US apontou a presença de aneurisma no território aortoilíaco em nove indivíduos, uma mulher e oito homens correspondendo a uma prevalência de 2,1 por cento, sendo 4,1 por cento em homens e 0,4 por cento em mulheres. Dois desses aneurismas estavam em artérias ilíacas ( um aneurisma em uma artéria ilíaca comum) e os demais sete na aorta abaixo das artérias renais. Os portadores de aneurisma de ilíaca säo homens. A prevalência do AAA foi de 1,7 por cento (7/411), sendo 3,1 por cento em homens e 0,4 por cento em mulheres. O EF indicou suspeita de presença de aneurisma em três desses pacientes. Outros seis pacientes näo tinham aneurisma. Considerando todos os aneurismas do território aortoilíaco, o EF teve sensibilidade de 33,3 por cento, especificidade de 99 por cento e valor preditivo positivo de 33,3 por cento. Considerando so AAA, a sensibilidade do EF foi de 42,8 por cento, a especificidade de 98,5 por cento e o valor preditivo positivo de 33 por cento. Nos 402 pacientes sem aneurisma arterial, o diâmetro máximo da aorta variou de 11 a 29 mm, com média de 16 ñ 21 mm. CONCLUSAO. A US é procedimento diagnóstico näo invasivo que deve ser utilizado em populaçäo idosa

[Prevalence of intraabdominal aneurysm in elderly patients]. / Prevalência de aneurisma intra-abdominal em idosos.

BACKGROUND: A study in old patients on the incidence of aneurysms in abdominal arteries (AAA) and on the maximum diameter of the aorta below the renal arteries in those patients without arterial dilatation. MATERIAL AND METHODS: The study comprised 411 individuals, 218 women and 153 men with an average age of 74.4 years. Physical examination of the abdomen (EF) and abdominal ultrasonography (US) were done, and the latter was considered the "golden standard" of reference. In relation to the aorta, it was considered as an aneurysm the maximum artery diameter larger than 30 mm and for the iliac arteries, the maximum diameter larger than 15 mm. RESULTS: The US showed the presence of aneurysm in the aortic-iliac territory in nine patients, one woman and eight men, corresponding to a prevalence of 2.1%, 4.1% in men and 0.4% in women. Two such aneurysms were in the iliac arteries (one aneurysm in a common iliac artery) and the other seven in the aorta below the renal arteries. The bearers of iliac aneurysm are men. The prevalence of the AAA was of 1.7% (7/411), 3.1% in men and 0.4% in women. The EF showed suspicion of the presence of aneurysm in 3 of these patients. The other 6 patients had no aneurysm. Considering all the aneurysms of the aortic-iliac territory, the EF had a sensitivity of 33.3%, a specificity of 99% and a positive prediction value of 33.3%. Considering only AAA, the sensitivity of the EF was 42.8%, the specificity 98.5%, and the positive prediction value, 33%. In the 402 patients without arterial aneurysm the maximum diameter of the aorta varied from 11 to 29 mm, with an average value of 16-21 mm. CONCLUSIONS: US is a non-invasive diagnostic procedure that should be used for the old age population.

Increasing safety belt use in a secondary enforcement state: evaluation of a three-county special enforcement program.

Special enforcement programs to increase belt use present a unique challenge in states with secondary enforcement laws. This paper reports findings from an evaluation of a combined public information and education/enforcement program to increase restraint use along a highly traveled corridor in three Michigan counties. This program (US-31 SAVE) was successful in increasing belt use at least temporarily along the special enforcement corridor. Observed belt use increased from a baseline rate of 56.7% to 65.1% during the program before slipping slightly to 62.7% after the intensive enforcement and PI&E declined (all differences significant at p less than .05). This paper details program and evaluation activities and suggests future research needs to better understand the most effective mix of public information and enforcement efforts in states with secondary belt use laws.