The Cutaneous Assessment Tool: development and reliability in juvenile idiopathic inflammatory myopathy.

OBJECTIVES: Clinical care and therapeutic trials in idiopathic inflammatory myopathies (IIM) require accurate and consistent assessment of cutaneous involvement. The Cutaneous Assessment Tool (CAT) was designed to measure skin activity and damage in IIM. We describe the development and inter-rater reliability of the CAT, and the frequency of lesions endorsed in a large population of juvenile IIM patients. METHODS: The CAT includes 10 activity, 4 damage and 7 combined lesions. Thirty-two photographic slides depicting IIM skin lesions were assessed by 11 raters. One hundred and twenty-three children were assessed by 11 paediatric rheumatologists at 10 centres. Inter-rater reliability was assessed using simple agreements and intra-class correlation coefficients (ICC). RESULTS: Simple agreements in recognizing lesions as present or absent were generally high (0.5-1.0). ICCs for CAT lesions were moderate (0.4-0.75) in both slides and real patients. ICCs for the CAT activity and damage scores were 0.71 and 0.81, respectively. CAT activity scores ranged from 0 to 44 (median 7, potential range 0-96) and CAT damage scores ranged from 0 to 13 (median 1, potential range 0-22). The most common cutaneous lesions endorsed were periungual capillary loop changes (63%), Gottron's papules/sign (53%), heliotrope rash (49%) and malar/facial erythema (49%). CONCLUSIONS: Total CAT activity and damage scores have moderate to good reliability. Assessors generally agree on the presence of a variety of cutaneous lesions. The CAT is a promising, semi-quantitative tool to comprehensively assess skin disease activity and damage in IIM.

Validation of the Childhood Health Assessment Questionnaire in the juvenile idiopathic myopathies. Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

OBJECTIVE: To examine the validity of the Childhood Health Assessment Questionnaire (CHAQ) in patients with juvenile idiopathic inflammatory myopathy (IIM). METHODS: One hundred fifteen patients were enrolled in a multicenter collaborative study, during which subjects were assessed twice, 7-9 months apart. Physical function was measured using the CHAQ. Internal reliability was assessed using adjusted item-total correlations and item endorsement rates. Construct validity was assessed by comparing predicted and actual correlations of the CHAQ with other measures of physical function and disease activity. Responsiveness was assessed by calculating effect size (ES) and standardized response mean (SRM) in a group of a priori defined "improvers." RESULTS: Item-total correlations were high (rs range = 0.35-0.81), suggesting all items were related to overall physical function. Manual muscle testing and the Childhood Myositis Assessment Scale correlated moderate to strongly with the CHAQ (r = -0.64 and -0.75, both p < 0.001). Moderate correlations were also seen with the physician global assessment of disease activity (rs = 0.58, p < 0.001), parent global assessment of overall health (rs = -0.65, p < 0.001), Steinbrocker function class (rs = 0.69, p < 0.001), and global skin activity (rs = 0.40, p < 0.001), while global disease damage and skin damage had low correlations (rs = 0.13 and 0.07, p > or =0.17). Responsiveness of the CHAQ was high, with ES = 1.05 and SRM = 1.20. CONCLUSION: In this large cohort of patients with juvenile IIM, the CHAQ exhibited internal reliability, construct validity, and strong responsiveness. We conclude that the CHAQ is a valid measure of physical function in juvenile IIM, appropriate for use in therapeutic trials, and potentially in the clinical care of these patients.

Assessing screening tests: extensions of McNemar's test.

We address the problem of comparing a new screening test to a currently available screening test in the absence of a gold standard. When both tests are given to each participant in a clinical trial, the usual analytical approach is to apply McNemar's test for equality of the off-diagonal probabilities, with rejection of the null hypothesis implying that the tests differ. For assessing equivalence, however, we consider a compound null hypothesis that the new test gives either fewer or more positive results than the standard. If both parts of this hypothesis are rejected, we assert equivalence in the rate of positive responses. We propose an extension of McNemar's test for this situation. A companion step is to construct a confidence interval for the ratio of the marginal probabilities and assert equivalence if the interval is sufficiently small. It is also important that the tests agree a large proportion of the time. This can be verified with a complementary two-tailed binomial test. Another situation arises when there is a gold standard for disease diagnosis, and we wish to compare the sensitivity and specificity of two screening tests. We show that a 2 degrees-of-freedom chi-square test based on two McNemar-like tables is an appropriate test.

Assessment of cerebral perfusion using quantitative EEG cordance.

Brain electrical activity is related to cerebral perfusion. The nature of this relationship is unclear, however, and surface-recorded activity has not been a reliable indicator of brain perfusion. We studied 27 subjects, all of whom were examined with single photon emission tomography (SPECT) and quantitative electroencephalography (QEEG), to assess associations between QEEG cordance and relative brain perfusion. Cordance has two indicator states: concordance, which may indicate high perfusion; and discordance, which may indicate low perfusion. We used multiple linear regression to assess the association between cordance and SPECT values, and found that cordance values were strongly associated with tissue perfusion. Concordance in the alpha band was associated both with mean tissue perfusion and the volume of normally perfused tissue, and it had a stronger association with perfusion than any other QEEG variable. Discordance in the beta 1 band was associated with mean perfusion, and it had a stronger association than did relative but not absolute power. These data suggest that cordance may be useful for the noninvasive assessment of brain perfusion.

Skin thickness score in systemic sclerosis: an assessment of interobserver variability in 3 independent studies.

OBJECTIVE: Using data from 3 independent studies, to quantify the interobserver reliability of semi-quantitative skin scoring methods (the original and the modified Rodnan skin thickness scores) used to assess the degree and extent of cutaneous thickening in systemic sclerosis (SSc). METHOD: Interobserver variability of the original Rodnan skin thickness score method (cutaneous thickness assessed in 26 body surface areas using a 0-4 scale) was evaluated in one study. The modified Rodnan method (cutaneous thickness assessed in 17 body surface areas using a 0-3 scale) was evaluated in 2 studies. In all 3 studies, each patient's skin thickness was assessed by 6 or 7 observers in a blinded fashion. RESULTS: The overall within patient standard deviations were not statistically different in all 3 studies (5.4, 4.6 and 4.6) irrespective of the overall mean skin thickness scores (26.6, 18.3 and 17.7). With the original Rodnan technique, the within patient standard deviation tended to be higher in patients with higher skin thickness scores. In the 2 studies which used the modified technique, no significant differences in within patient standard deviation were noted between high and low skin thickness scores. CONCLUSIONS: Three independent studies demonstrate that the Rodnan skin thickness scoring techniques are reproducible among different observers (the within patient standard deviation being consistently about 5 units). Our data provide valuable information needed for sample size calculations for SSc trials in which skin thickness score is an outcome variable.

On the sample size for studies based upon McNemar's test.

When computing the sample size for studies using McNemar's test, one needs to know the probability of discordance and the odds ratio to be detected. In many studies, the investigator is unable to specify the probability of discordance, but can state, at least approximately, the marginal probabilities of each variable. This information leads to restrictions on the possible values of the cell probabilities and provides a range of admissible values for the off-diagonal cells. We compute the sample size needed in these circumstances and compare them to the results cited by Schlesselman and Connett et al. These sample sizes for the method are quite close to those found in the Monte Carlo study of Connett et al.

Practice based evaluation of the longterm benefit of second line agents in rheumatoid arthritis.

A hypothetical practice based consortium to evaluate treatment of early rheumatoid arthritis (RA) is discussed. It would consist of a coordinating center and many practicing rheumatologists. Patients with RA within 3 to 12 months of disease onset who met strict entry criteria would be offered enrollment in their choice from a menu of protocols that includes standard and aggressive treatment options and would be followed for a long time. Standard efficacy assessments would be carried out at fairly long intervals, with emphasis on erosive changes in wrist, hands and feet x-rays. Analysis would be done across drug protocols within homogeneous subgroups of patients who have been stratified by comparable entry characteristics, using those who develop erosions during treatment with nonsteroidal antiinflammatory drugs only as the standard for comparison. This approach can be used to identify risk factors that predict subsequent erosive joint damage, and to select a few promising drugs, combinations and therapeutic strategies for subsequent definitive studies.

Adjusting employer group capitation premiums by Community Rating by class factors.

Community rating of employer group health maintenance organization (HMO) capitation premiums results in low premiums for some groups and high premiums for other groups, as compared with the marginal costs of providing services. In effect, low health risk groups are cross subsidizing high health-risk groups in an HMO. This has caused several inefficiencies in the health plan marketplace, which have directly benefited higher-risk groups. For this reason, certain low-risk groups are searching for new strategies to improve market efficiency. One strategy is Community Rating by Class (CRC), a system which adjusts community rated capitation premiums by broad-based risk factors. This article examines CRC as a strategy to help reduce the inefficiencies caused by current federal regulations. In regressions predicting future year total family health expenditures, the CRC Model achieved an R2 value of 0.211. This value was over half the R2 value of an experience rated approach, based on prior year utilization and expenditure variables. Family size accounted for 80% of the variance explained by the CRC Model. The results indicate that the CRC rating approach may be a good mechanism to correct for cross subsidization of employer group capitation premiums.

A financial analysis of Hodgkin lymphoma staging.

A clinical algorithm was developed for staging of Hodgkin disease. This represented the treatment logic employed in a specified time period and was used to categorize charges incurred in the staging of 50 consecutive patients who underwent this process at a university hospital. Charges were categorized as: necessary (in concordance with the algorithm), justifiable (a result of care for a separate medical disorder or for consideration of distance), and perceived excess (neither necessary nor justifiable). Thirty per cent of the total charges were identified as perceived excess. Hospitalization accounted for 68 per cent and laboratory charges 22 per cent of the perceived excess charges. Fifty-eight per cent of the patients had a percentage of perceived excess bed charges exceeding 30 per cent of the total. Perceived excess medical hospitalization correlated positively with time from diagnosis to treatment decision. It is recommended that attempts to reduce the expense of Hodgkin lymphoma staging be directed at decreasing hospitalization.

Motivational factors affecting contraceptive use.

PIP: 95% of married and unmarried women who were delivered at North Carolina Memorial Hospital during the summers of 1968-1969 were interviewed on Day 2 or 3 postpartum to determine: 1) knowledge of contraceptive methods, 2) consistency of contraceptive use related to this and other pregnancies, 3) reason for desired family size, 4) number of planned pregnancies, and 5) demographic data relating to age, sex, and education. From a Negro southern rural population in North Carolina, 126 Negro and 132 Caucasian married women were interviewed and completed the Neuroticism Scale Questionnaire (NSQ) which is derived from items on the 16 Personality Factor Questionnaire discriminating neurotic from normal patients. The NSQ's 4 factors are: 1) submissiveness vs. dominance, 2) sensitivity vs. practicality and/or insensitivity, 3) depression vs. happy-go-lucky cheerfulness, and 4) anxiety. Both groups were similar in age but there were significant educational differences (education beyond high school: Negroes, 8%; Caucasians, 58%). While knowledge of contraception was similar, Negro women reported more unwanted pregnancies, more inconsistent use of contraception, and a higher response to the NSQ. There were significant differences on 4 of the 5 NSQ items; only anxiety showed no difference in the groups studied. Negro women 1) clustered themselves at the extremes of the sensitivity factor, 2) scored themselves as significantly more cheerful and extroverted, 3) scored themselves as more submissive, and 4) scored significantly higher on the total neuroticism score. Nearly 1/2 of the Negro women reported significant opposition from husbands regarding use of contraception, and evidence seemed to indicate that these women found an important source of self-esteem in childbearing. Measures to prevent conception in these women must provide alternate modes of gratification to replace that of motherhood.^ieng