Risk adjustment of Florida mental health outcomes data: concepts, methods, and results.

This article discusses outcome evaluation systems for mental health programs. It reviews and critically evaluates design and analysis methods for strengthening the validity of such uncontrolled comparisons. The article examines methods for statistically adjusting preexisting groups, now referred to as risk adjustment or case-mix adjustment, and offers guidelines for determining when this procedure is appropriate. Then, analyses on two dependent variables--a global rating of functioning and a consumer satisfaction measure--available from an outcomes evaluation system currently underway in Florida are used to demonstrate the proposed method of risk adjustment. Results for 24 providers of mental health services showed that while risk adjustment only made a small difference in the overall provider rankings, the ranking of some specific providers changed considerably. The article concludes with a discussion of the implications of this research.

Effects of superparamagnetic iron oxide on radio-frequency-induced temperature distribution: in vitro measurements in polyacrylamide phantoms and in vivo results in a rabbit liver model.

PURPOSE: To determine whether contrast medium containing superparamagnetic iron oxide (SPIO) alters radio-frequency (RF)-related temperature distribution in acrylamide phantoms and in an in vivo model. MATERIALS AND METHODS: In nine acrylamide phantoms with increasing SPIO content, RF was applied with simultaneous measurement of temperature profile along the probe track. Additionally, magnetic resonance imaging-guided RF ablation was performed in the liver of six rabbits after the intravenous administration of SPIO (0.05 mL per kilogram of body weight) 40 minutes prior to ablation (SPIO group) and in another six rabbits without prior SPIO administration (control group). Coagulation diameter was evaluated on the basis of postprocedural imaging and subsequent gross pathologic findings. Statistical analysis was performed with the Student t test. RESULTS: In the phantoms, progressive increases in iron content resulted in higher temperatures along the RF electrode track (P < .05). In the in vivo model, however, SPIO at physiologic concentrations did not significantly increase the diameter of coagulation on the basis of either postprocedural imaging or subsequent gross pathologic findings. Additionally, no significant differences were seen in other RF-related parameters including impedance, voltage, current, and grounding pad temperature. CONCLUSION: Administration of SPIO in conjunction with RF ablation of focal liver lesions is feasible and safe, but no significant difference in the extent of induced coagulation can be expected.

MRI-guided radiofrequency thermal ablation of implanted VX2 liver tumors in a rabbit model: demonstration of feasibility at 0.2 T.

Successful radiofrequency (RF) thermal ablation was performed on VX2 tumors implanted in 23 rabbit livers under magnetic resonance (MR) guidance using a C-arm-shaped low-field 0.2 T system. RF application and immediate postprocedure MRI of all animals was performed [T2-weighted, turbo short tau inversion recovery (STIR), T1-weighted before and after gadopentetate dimeglumine administration). Follow-up MRI with a superparamagnetic iron oxide (SPIO) contrast medium was performed in nine rabbits at 2 weeks and in four rabbits at 1 month post RF ablation. All livers were harvested for pathologic examination. T2-weighted and turbo-STIR images demonstrated the highest tumor-to-RF-thermal lesion contrast-to-noise ratios (CNRs; means 4.5 and 3.8, respectively) on postprocedure images; this was redemonstrated at 2- and 4-week follow-up imaging. T2-weighted imaging never overestimated pathologic lesion size by more than 2 mm, and the radiologic-pathologic correlation coefficient was not less than 0.90. In conclusion, MRI-guided RF thermal ablation in implanted liver tumor is feasible using a C-arm-shaped low-field 0.2 T system. The thermal lesion size can be most accurately monitored with T2-weighted and turbo-STIR images.

MR monitoring of MR-guided radiofrequency thermal ablation of normal liver in an animal model.

The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r2 value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease.

Metastases to the pancreas.

Disparity in prognosis and management between primary and secondary pancreatic tumours makes recognition of metastases to the pancreas on CT and MRI an important goal. Three different patterns of secondary pancreatic tumours may be seen: localized, multifocal, or diffuse enlargement. CT findings include hypodense lesions, which show rim enhancement following intravenous contrast medium. On MR examination, the lesions are usually hypointense on T1 weighted and hyperintense on T2 weighted images.

HIV risk factors for persons with serious mental illness.

HIV risk factors were assessed among 120 persons in treatment for serious mental illness. Although subjects had good general knowledge regarding HIV, many engaged in high risk behaviors. Condom use was infrequent among those who had multiple sexual partners, and sharing needles was common for those who used i.v. drugs. Clearly, factual knowledge about HIV was not sufficient to prevent risky behavior. Nearly half of the sample was categorized as at medium to high risk, and almost half of the participants, especially those at medium risk, underestimated their own level of risk. The results suggest that education and intervention strategies should focus on increasing the accuracy of the individual's risk assessment as well as changing attitudes towards condoms and improving skills in using condoms. Assessing personal risk and adopting risk-reduction strategies are the keys to successful AIDS prevention for persons with serious mental illness.

Assisting clients of community mental health centers to secure SSI benefits: a controlled evaluation.

The entire caseloads of three Community Mental Health Centers were screened on variables normally assessed in the SSI application process. These data were then used to classify each individual as Possibly Eligible for SSI benefits, or as Probably Not Eligible. The Possibly Eligible subjects were randomly assigned to either the Experimental condition, in which subjects were helped to apply for SSI, or the Control condition, in which no intervention was provided. Results showed that the Experimental subjects were almost twice as likely to secure SSI benefits as the Control subjects. The usefulness of the screening form was supported in that control subjects were almost five times more likely to be awarded SSI, compared with subjects who had been classified as Probably Not Eligible.

Speed of scanning in primary memory in persons with dementia of the Alzheimer type.

The nature of the search of primary memory by persons with a presumptive diagnosis of mild Alzheimer's disease (DAT) was compared with that of normal elderly and young persons using the Sternberg (1966) paradigm. DAT subjects evidenced a substantial deficit in the speed of scanning in primary memory and a deficit in at least one other stage of processing. These findings are consistent with the hypothesis that the decline in memory performance evidenced by persons with DAT may be attributable to an increase in the time requirements of mnemonic processing.

Reliability and validity of the Florida Sexual History Questionnaire.

The Florida Sexual History Questionnaire (FSHQ) is a brief 20-item questionnaire designed to assess male sexual dysfunction. The validity and reliability of the scale were examined in 33 diabetic impotent males and 58 nondiabetic, age-equivalent nonimpotent males. The FSHQ was found to have high internal consistency and split-half reliability and significantly discriminated between nonimpotent and impotent subjects. Among diabetic impotent subjects, some of the test items were correlated significantly with physiological measures of sexual functioning. However, the FSHQ failed to discriminate between diabetics diagnosed as having organic or psychogenic impotence. This latter finding is discussed within the context of recent suggestions that it may not be possible to draw a clear dichotomy between organic and psychogenic impotence.

An evaluation of the Minnesota Multiphasic Personality Inventory as a discriminator of primary organic and primary psychogenic impotence in diabetic males.

The ability of the MMPI to discriminate between primary psychogenic impotence and primary organic impotence in males with diabetes mellitus was assessed. In order to provide the MMPI with the optimal situation to discriminate between the two groups, we attempted to form a homogeneous sample in terms of physical conditions. Thirty impotent diabetic males were classified as primary organic or primary psychogenic based on nocturnal penile tumescence data. Beutler et al.'s MMPI decision rules yielded a 63% misclassification of the two groups. Possible explanations for the lack of discriminative power of the MMPI with this sample of diabetic males were discussed in relation to previous findings. The power of nocturnal penile tumescence to classify men as having primary organic or primary psychogenic impotence was examined with reference to other vascular and endocrine variables.

Brain potentials related to seeing one's own name.

Subjects were assigned an assumed name and then shown a series of statements of the form, "My name / is / X", where X was the assumed name, their own first name, or one of a set of other false names. Their task was to respond positively to the "assumed" name and reject as false all other names, including their own. An N380 feature of the averaged task-related brain potentials, considered to be inversely related to the degree of contextual priming, was greatly enhanced for the false names compared to the assumed name. The N380 to one's own name was more similar to that of the false than the assumed name, indicating that the sentence context's priming of various names was under the subjects' attentional control, and that the late negativity could be modulated by this attention. In contrast, a large P510 feature distinguished one's own name from the false name, and this difference was unaffected by practice. Even in cases, then, where the context allows anticipation of one verbal event (here, the assumed name), a highly overlearned and salient stimulus such as one's own name continues to produce a distinctive neural response.

Event-related potentials: a critical review of methods for single-trial detection.

The analysis of ERP data has followed several lines over the last 20 years. The most prevalent method is simply to average ERPs for a given class of stimuli. The ERPs are compared for differences across classes of stimuli. Little other special data processing is used. The ERP comparisons are usually performed using visual examination of the wave-shapes. Sometimes statistics are calculated such as means, variances, and confidence limits. Linear filtering is used to reduce interference. Another approach is to model or analyze the ERP as a sequence of vectors or frames of data samples. These samples may be of the ERP time waveform or they may be of the frequency transform of the ERP waveform. The frames of data vary in length from the entire ERP waveform (500 to 1000 msec) to frames as short as ten sample points (100 msec). Recognition of an event in the ERP is achieved by computing a distance measure between parameter vectors for one class of stimuli and corresponding parameter vectors for another class of stimuli. Recognition is achieved by selecting the ERP with the lowest distance score. This approach is "pattern matching" and relies on two assumptions: adjacent frames of data are uncorrelated, and the variability of the data can be accounted for by the distance measured for all stimuli in the classes presented. Subject variability is generally not accounted for, other than to assume it is the same for all classes of stimuli. The data are clustered into a variety of reference patterns that represent particular manifestations of a particular stimulus. Another approach is "feature-based" recognition. The idea is to identify and automatically extract features of the data that can provide a characterization of stimuli. The features selected may be abstract. They are calculated from the data or transforms of the data.

The effect of daylength and level of feeding on serum prolactin in growing lambs.

Twenty-four castrated male lambs initially maintained on a photoperiod of 12 h light:12 h dark were allocated to a factorial experiment with two daylengths (8 h L: 16 h D or 16 h L: 8 h D) and two levels of feeding (restricted or ad libitum). Blood samples were taken every 4 h for 24 h during the introductory period and after 24, 51 and 79 days of treatment. There were highly significant positive effects of daylength and level of feeding on serum prolactin: mean concentrations increased from a mean of 38 plus or minus 1 ng/ml during the introductory period until at day 79 they were: 8L: 16D (restricted diet), 81 ng/ml; (food ad libitum), 167 ng/ml; 16L:8D (restricted diet), 262 ng/ml; (food ad libitum), 262 ng/ml (S.E. of treatment mean plus or minus 4). Long daylength and feeding ad libitum also significantly increased growth rate.