Rates of weight change for black and white Americans over a twenty year period.

OBJECTIVE: To examine the rate of weight gain over time among Americans by age, gender, and race. PARTICIPANTS: Scientific sample of 5117 Americans, ages 25-74 y in 1971 followed for 20 y. RESULTS: Rates of weight gain estimated by mixed effects models are highest among young adults and rates of weight loss are greatest among older adults. The overall shape of the growth curves are similar for men and women, black and white, in terms of both weight gain and weight loss. Rates are also affected by baseline body mass index (BMI=wt in kg/height in m(2)). CONCLUSIONS: Americans gain weight until middle age, stabilize, and begin to lose weight near age 60. Weight loss during old age is especially evident for obese Americans. The ability to accurately identify groups with increased risk and target them for obesity prevention will help combat the steady rise of overweight and obesity in America.

Role of lateral cephalograms in assessing severity and difficulty of orthodontic cases.

To assess the role of lateral cephalometric films in the evaluation of orthodontic patients, 16 certified orthodontists examined 80 sets of dental casts and lateral cephalograms. The patients included 5 subgroups: Class I with mild crowding, Class II Division 2, Class III, open bites, and bimaxillary protrusion. A 5-point Visual Analogue Scale was used to assess the degree of severity and difficulty of each case. Severity was defined as the degree of deviation from ideal occlusion, while difficulty was defined as the probability of attaining an ideal occlusion when all treatment options were available. The examiner then chose one or more of the following treatment options: growth modification, extraction, nonextraction, and surgery. All examiners scored the degree of severity and difficulty of each case with casts only at Time 1 (T1), then with casts and cephalograms at Time 2 (T2). The observed ratings from the Visual Analogue Scale were scored by using the Rasch model, which transforms the nonlinear ordinal ratings to a linear interval scale. Intersubgroup differences and differences between T1 and T2 difficulty and severity were assessed by using a 5 x 2 repeated measures analysis of variance. A paired t test examined the amount and direction of the differences between T1 and T2 of each subgroup. Multiple contingency tables were used to compare treatment option changes between all subgroups at each time. Severity and difficulty scores highly correlated. Analysis of variance showed significant differences among subgroups for both severity and difficulty; however, there were significant time differences for severity only. Paired t tests revealed a small increase in severity for the bimaxillary protrusive group and small but significant decreases for the subgroups Class II Division 2 and Class III when cephalograms were added. The multicontingency table analysis demonstrated that a significant number of examiners did change their treatment options at T2 for bimaxillary protrusive, nonextraction, and Class II Division 2 patients. It was concluded that lateral cephalometric films showed a significant influence on a clinician's determination on severity of some types of orthodontic malocclusions.

History of affective disorder and the temporal trajectory of fatigue in rheumatoid arthritis.

This study examines whether the general level and rate of change of fatigue over time is different for those rheumatoid arthritis (RA) patients with and those without a history of affective disorder (AD). Four hundred fifteen RA patients from a national panel had yearly telephone interviews to obtain fatigue and distress reports, and a one-time semistructured assessment of the history of depression and generalized anxiety disorder Growth-curve analysis was used to capture variations in initial fatigue levels and changes in fatigue over 7 years for those with and without a history. RA patients with a history of major AD reported levels of fatigue that were 10% higher than those without a history in the 1st year of the study. Their fatigue reports remained elevated over 7 years. Further analysis showed that the effects of a history of AD on fatigue are fully mediated through current distress, although those with a history had a significantly smaller distress-fatigue slope. Thus, a history of AD leaves RA patients at risk for a 7-year trajectory of fatigue that is consistently higher than that of patients without a history. The elevation in fatigue reports is, at least in part, a function of enduring levels of distress.

Measuring disability: application of the Rasch model to activities of daily living (ADL/IADL).

This paper describes a comparative analysis of (ADL) and (IADL) items administered to two samples, 4,430 persons representative of older Americans, and 605 persons representative of patients with rheumatoid arthrisit (RA). Responses are scored separately using both Likert and Rasch measurement models. While Likert scoring seems to provide information similar to Rasch, the descriptive statistics are often contrary if not contradictory, and estimates of reliability from Likert are inflated. The test characteristic curves derived from Rasch are similar despite differences between the levels of disability with the two samples. Correlations of Rasch item calibrations across three samples were .71, .76, and .80. The fit between the items and the samples, indicating the compatibility between the test and subjects, is seen much more clearly with Rasch with more than half of the general population measuring the extremes. Since research on disability depends on measures with known properties, the superiority of Rasch over Likert is evident.

Measuring disability: application of the Rasch model to activities of daily living (ADL/IADL).

This paper describes a comparative analysis of (ADL) and (IADL) items administered to two samples, 4,430 persons representative of older Americans, and 605 persons representative of patients with rheumatoid arthrisit (RA). Responses are scored separately using both Likert and Rasch measurement models. While Likert scoring seems to provide information similar to Rasch, the descriptive statistics are often contrary if not contradictory, and estimates of reliability from Likert are inflated. The test characteristic curves derived from Rasch are similar despite differences between the levels of disability with the two samples. Correlations of Rasch item calibrations across three samples were .71, .76, and .80. The fit between the items and the samples, indicating the compatibility between the test and subjects, is seen much more clearly with Rasch with more than half of the general population measuring the extremes. Since research on disability depends on measures with known properties, the superiority of Rasch over Likert is evident.

Geographic assessment of breast cancer screening by towns, zip codes, and census tracts.

Early detection is the primary way to control breast cancer, and mammography screening can reduce breast cancer mortality 30 to 40 percent among women aged 50 years and older. Geographic areas with a high proportion of cases with late-stage diagnoses may reflect gaps in screening efforts. We used a spatial scan statistic, adjusting for the multitude of possible region locations and sizes, to test whether any particular region of Massachusetts had statistically significant excesses of late-stage diagnoses during the period 1982 to 1986. The novel geographic analysis technique utilized here can also be used in the control of other types of cancer.

Can structural equation models inform blood pressure research?

OBJECTIVE: To show how structural equation models might be used to better understand the ways in which risk factors influence blood pressure. METHODS: Nine measurements on 2009 women and 1518 men for whom there was complete data both at time 1 and at time 8 of the Framingham Heart Study were used to test a hypothetical model of how risk factors such as age, obesity, smoking, vital capacity, and heart rate influence each other and blood pressure. The hypothetical model was translated into structural equations and tested against the data. RESULTS: The hypothetical model fits the data for women at time 1 very well with a chi2=15.41 which, with 14 degrees of freedom, has P=0.32 and indicates there is no difference between the covariance structure generated by the hypothetical model and the covariance structure generated by the data. The same model was tested for women at time 8 and for men at times 1 and 8 also and fit almost as well. Age and percentage of ideal weight of subjects exert the strongest influence on systolic blood pressure, whereas the effect of age on diastolic blood pressure seems less consistent. Smoking has no direct effect on blood pressure, but it does have a small effect on heart rate and a negative effect on obesity, suggesting, perhaps, that, while it has no direct effect, it does play an indirect role. CONCLUSIONS: Structural equation models can be used by researchers trying to understand how risk factors can influence blood pressure in complex ways. The methodology is especially appropriate for testing competing conceptual models.

Stress and low birth weight: a structural modeling approach using real life stressors.

This study presents a structural equation model describing the influence of stressful life experiences on low birth weight. Data were gathered prospectively in two waves from 5295 inner-city women as part of a city-wide preterm birth prevention project. Using interviews and the medical record, over 200 measures were gathered on each mother and her infant, where each measure was included because of its relevance documented in the risk factor literature. Seventeen of these measures reflected real life stressful experiences and through measurement modeling, eleven of these measures were chosen to represent three underlying measures of stress: economic stress, family stress, and the lack of social support. This study incorporates these psychosocial stressors into a full structural equation model to show their influence on addictive behavior and low birth weight. The full model emerged from tests of alternative causal conceptualizations of how these stressors influence each other and low birth weight--whether their influence on low birth weight in simple and direct, or whether their influence is mediated by addictive behaviors. The model was tested on the first wave, a sample of 3205, and cross-validated on the second wave, a sample of 2090. The model shows that economic stress influences both social support and family stress, but has no direct influence on low birth weight: that social support, or its absence, influences addictive behavior, but has no direct influence on low birth weight, and that family stress influences addictive behavior, and consistent with 30 years of research on humans, has no direct influence on low birth weight. Finally, the mother's history of medical risks shows an independent influence on low birth weight, while her age does not. Age, however, shows a strong influence on addictive behavior. The study demonstrates how structural equation modeling can be used to create and test alternative conceptualizations of how stress affects low birth weight. There are strong implications for planners of prenatal care programs.

Characteristics of surgeons with high and low malpractice claims rates.

We studied the relationship of malpractice claims and the personal, educational, and practice characteristics of a sample of surgeons (n = 427). The surgeons were members of a physician-owned malpractice trust and represented all those who had fewer than 0.13 malpractice claims per year and those with more than 0.54 claims per year. Data are reported separately for orthopedic surgeons (148), obstetrician-gynecologists (115), and a mixed group of other surgeons (164). The last group included otolaryngologists, neurosurgeons, and general, vascular, thoracic, and plastic surgeons. We studied the relationship between the number of malpractice claims (ranging from no history of claims to those terminated from the trust because of high rates of claims) and the surgeon's personal, educational, and practice characteristics. The major differences were between the surgeons who were terminated because of a high number of claims and those with few or no claims. Terminated surgeons were less likely to have completed a fellowship, belong to a clinical faculty, be members of professional societies, be graduates of an American or Canadian medical school, have specialty board certification, or be in a group practice. The data also suggest that orthopedists with high numbers of claims may be less likely to have a religious affiliation or to have a registered nurse working in their office practice. These findings suggest that surgeons with lower claim rates may be more likely to manifest exemplary modes of professional peer relationships and responsible clinical behavior.

Moral reasoning and malpractice. A pilot study of orthopedic surgeons.

The relationship between moral reasoning and malpractice claims was studied in 53 orthopedic surgeons. Levels of moral reasoning were defined by the percentage of principled responses (P-score) on Rest's Defining Issues Test, while annualized rates of malpractice claims were computed on the basis of data from a regional, physician-owned, interindemnity/liability protection trust. Orthopedic surgeons with fewer than 0.20 claims per year demonstrated significantly (P = 0.04) higher levels of moral reasoning (mean P-score of 43.8) than did those with claims rates higher than 0.40 claims per year (mean P-score of 38.0). Only 1 of 13 orthopedists with P-scores over 50 was found in the higher claims group, suggesting that high levels of moral reasoning may provide a protective element against malpractice claims.

Creating a psychosocial measurement model from stressful life events.

Some have argued that failure to find evidence of a link between psychosocial stress factors and birth outcomes in humans may be attributed to a restriction in the range of measures used to characterize stress severity. This study describes the process of building and testing a measurement model from real life stressful experiences. To create a conceptual model, seven life events identified as stressful by successive samples of 3205 and 2090 Hartford inner city women between 1987 and 1992 and ten other experiences identified as potentially stressful were submitted to 10 academic colleagues and 4 health professionals associated with a preterm birth prevention project. Each rater attempted to identify a meaningful conceptual structure for clustering these psychosocial stressors. Seven of the thirteen proposed models were suitable for testing by means of structural equation modeling. Three models emerged as conceptually close and statistically acceptable with the number of information laden stressors dropping from 17 to 11 and clustering to form three latent variables representing economic, social support, and family stressors. The root mean square error of approximation was 0.03, where a value as low as 0.08 represents an adequate fit, and the generalized fit index was 0.99. The final model was cross-validated on the second sample where these and other fit indices were similar, indicating that a structurally meaningful measurement model fit the data well and could be used to investigate further the relationship of these theoretical variables to birth outcomes.

Gender, paid work, and symptoms of emotional distress in rheumatoid arthritis patients.

OBJECTIVE: To evaluate the relative contribution of gender-related work conditions, gender-related socialization practices, and disease characteristics to the explanation of emotional distress in men and women with rheumatoid arthritis (RA). METHODS: Three hundred sixty-nine RA patients who were employed outside the home were recruited from a national randomized sample of rheumatology practices. Data on paid work and disease characteristics were obtained by telephone interview. Emotional distress was measured by the Center for Epidemiological Studies Depression (CES-D) scale. Hierarchical ordinary least-squares regression was used to assess the relationship of sex, class, work characteristics, and disease characteristics to both the CES-D summary scale and the CES-D factor structure. RESULTS: Differences in emotional distress were explained best by functional ability and pain and secondarily by the characteristics of paid work, with no independent effect for sex. Distress increased with decreasing functional ability, increasing pain, and exposure to such work characteristics as low autonomy, low income, and high demands. No sex differences in any of the CES-D subscales remained after controlling for disease and work variables. CONCLUSION: Among employed RA patients with high levels of functional disability and exposure to stressful work characteristics, men and women are at equal risk of experiencing emotional distress.

The measurement structure of the Center for Epidemiologic Studies Depression Scale.

This study examined the temporal stability of the measurement structure of the Center for Epidemiologic Studies Depression Scale (CES-D; Radloff, 1977) in 813 individuals with rheumatoid arthritis. Participants completed the CES-D (Radloff, 1977) on three occasions 1 year apart. Structural equation models and polyserial correlations were used to address methodological limitations of previous studies. Four competing measurement structures were tested with one factor, three factors, four factors, and a single second-order factor underlying the four-factor model. The four-factor and the second-order-factor models provided the best fit at Time 1. When cross-validated at Times 2 and 3, the four-factor and the second-order-factor models remained invariant. Researchers can now more confidently use the CES-D to examine how distress changes in chronic physical disorders.

Rheumatology education in an undergraduate program of physical therapy. A new outlook.

Few physical therapy education programs offer formal rheumatology courses taught by specialists in the field of rheumatic diseases. We modified, evaluated, and formalized a rheumatology course for undergraduate physical therapy students taught by a rheumatologist and a specially trained physical therapist. Although the course is applicable to our undergraduate program, the process we used to modify and evaluate the course content could be useful to others in their development of similar courses elsewhere. Our intent in discussing this process, the course content, and the rationale for our study is to stimulate a national review of rheumatology course content in physical therapy education programs.

Evaluation of a computer based education lesson for patients with rheumatoid arthritis.

A computer based education (CBE) lesson was developed for patients with rheumatoid arthritis (RA) and evaluated using a controlled experiment. There were statistically significant differences in the CBE group compared with controls in knowledge gained (p less than 0.01), improved outlook on life (p less than 0.01), hopefulness of a good prognosis (p less than 0.01), decreased belief in the role of luck or fate in determining their health (p less than 0.05) and reported increase in use of behaviors such as joint protection (p less than 0.02) and rest (p less than 0.05). The lesson was accepted and enjoyed by the patients.

Moral reasoning as a criterion for admission to medical school.

To determine whether admission interviews could differentiate applicants on their personal qualities (such as integrity, empathy and commitment) 456 applicants from two medical schools were tested on the Defining Issues Test (DIT), which measures the amount of principled or post-conventional moral reasoning. No difference was found between the DIT scores of the accepted and the rejected applicants of the school in which the admission criteria are the traditional scholastic ones. On the other hand, a great difference was shown in the school which admits students for their personal characteristics as assessed by interviews. Yet only moderate correlation was shown between the DIT and the interview scores. Since moral reasoning is a key concept in medical professional behaviour and is correlated with clinical performance, the findings deserve special attention. A possible use of the DIT in the student selection process is discussed.