Depression determines illness conviction and pain impact: a structural equation modeling analysis.

OBJECTIVE: The present study sought to derive an algorithm using factor analysis and structural equation modeling (SEM) to describe headache and orofacial pain patients using measures of behavioral and psychological functioning. This investigation further examined whether the underlying factor structure differed in 3 presumed distinct diagnostic categories: myofascial, neuropathic, and neurovascular pain. DESIGN: The Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Multidimensional Pain Inventory (MPI), Beck Depression Inventory-II (BDI-II), and visual analog scale for functional limitation (VAS-FL) were administered to the subjects. A split group design was used. Exploratory factor analysis (EFA) was used to describe distinct factor domains in the first group. Confirmatory factor analysis (CFA) using SEM tested this structure in the second group and described causal relationships between the revealed (latent) factors. Analysis of variance (ANOVA) was used to test for differences in demographic variables and diagnostic group factor structure. SETTING: The Pain Center is a comprehensive, multidisciplinary pain medicine program at Cedars-Sinai Medical Center, Los Angeles, California. SUBJECTS: Three hundred and ninety (N = 390) subjects were assigned to 1 of 3 diagnostic categories: myofascial pain syndrome, neuropathic pain, or neurovascular pain. RESULTS: EFA revealed a 3-factor solution. The factors were labeled Depression, Illness Conviction, and Pain Impact, reflecting the content of their respective variables with highest loadings. CFA using SEM validated the 3-factor solution, and further revealed that Depression was a critical causal factor determining Illness Conviction and Pain Impact. No causal relationship was observed between Illness Conviction and Pain Impact. ANOVA found no differences in demographics. No difference in factor structure emerged for the 3 diagnostic categories. CONCLUSIONS: Analysis derived a 3-factor solution. The factors were Pain Impact, Illness Conviction, and Depression. SEM revealed the critical causal pathway showing that Depression determined Illness Conviction and Pain Impact. We conclude that the main target for pain treatment is depression. No differences in factor structure were found for the 3 diagnostic categories of myofascial, neuropathic, or neurovascular pain. This suggests that psychological processes are similar in chronic headache and orofacial pain patients despite their presumed distinct underlying pathophysiological mechanisms. SME is a powerful methodology to construct causal models that has been underutilized in the pain literature.

Seat-belt use and relation to neurologic injury in motor vehicle crashes.

The relation between seat-belt use and neurologic injury was examined for the 1,352 patients who had spinal injuries as the result of motor vehicle crashes and were subsequently admitted to the Midwest Regional Spinal Cord Injury Center at Northwestern University between 1971 and 1993. Intact lesions were observed in 44% of patients (Frankel level E), complete lesions in 28% (Frankel A), sensory intact lesions in 8% (Frankel B), motor intact lesions in 5% (Frankel C), and functional motor lesions in 14% (Frankel D). Whereas only 14% of the sample were wearing seat belts, 60% of the belted and 41% of the unbelted vehicle occupants had intact lesions. The odds of surviving a motor vehicle crash with an intact injury were greater for patients who were wearing a lap or shoulder belt (odds = 1.57) for women (odds = 0.63) and for patients whose injury occurred more recently (odds = 1.05). The relation between position in the vehicle and extent of injury was strongest for rear passengers: intact lesions were sustained by 73% of belted and 35% of unbelted rear passengers, whereas complete lesions were sustained by 9% of the belted and 21% of the unbelted rear passengers. In conclusion, seat belts appear to be an effective means of decreasing the extent of neurologic deficit in those sustaining spinal injuries caused by motor vehicle crashes. The results of this study support injury-prevention efforts that emphasize lap- and shoulder-belt use.

Relationships between disability measures and nursing effort during medical rehabilitation for patients with traumatic brain and spinal cord injury.

OBJECTIVE: The increasing use of disability measures requires that the validity of these instruments be adequately demonstrated. This study sought to evaluate the concurrent validity of one disability measure, the Functional Independence Measure (FIMSM) using minutes of care reported by nursing staff. STUDY DESIGN: Correlational, cohort design. SETTING: Eight inpatient medical rehabilitation hospitals that subscribe to the Uniform Data System for Medical Rehabilitation. PATIENTS OR OTHER PARTICIPANTS: 129 patients with traumatic brain injury (TBI) and 53 patients with traumatic spinal cord injury (SCI). INTERVENTIONS: Routine rehabilitation care. MAIN OUTCOME MEASURES: Patient-nurse contact times were recorded with a stop watch for a 24-hour period during the first and last weeks of inpatient rehabilitation. The FIM was also completed during the first and last weeks of rehabilitation. RESULTS: Contact times declined from the first to last weeks of rehabilitation, concurrent with improving scores on motor and cognitive measures derived from the FIM. Statistically significant correlations between contact times and FIM measures were observed for medication dispensing, treatment provision, and teaching/activities of daily living at admission and discharge. Smaller and usually nonsignificant correlations were observed in activities that did not involve direct patient contact. Contact times increased exponentially as disability increased. CONCLUSIONS: These results support the construct validity of the FIM by demonstrating strong relationships (r values in the range of .40 to .60) between burden of care and a measure of disability.

Paracetamol prescribing habits in a children's hospital.

AIM: Paracetamol is an analgesic/antipyretic widely used in children. The drug can cause hepatic and renal damage due to cumulative toxicity when used in excess of 90 mg/kg@day. There are no dosing guidelines for paracetamol use in children under 1 month of age. We wished to discern current paracetamol prescribing habits in order to establish safety of current practices and offer recommendations towards rational use. METHODS: An anonymous questionnaire was sent to all medical staff working in a university childrenís hospital. We sought information about paracetamol prescribing regimes for children 4 months and over, 3 months and under and neonates in the first 2 weeks of life. Pharmacists audited daily prescription charts of inpatients without hepatic or renal disease over a 2 month period. The maximum possible daily dose was calculated for each child and note was made if a dose in excess of 95 mg/kg was given. RESULTS: There were 53 respondents to the 80 questionnaires posted. There was a trend to use lower daily doses in the younger age group. Similarly, more practitioners either did not use or did not know safe dosing schedules in children 3 months and younger. During the 2 month period there were 823 prescriptions for children 4 months and over, 85 for infants 3 months and under and seven for under 2 week old neonates. In the children 4 months and over 25 of 140 prescriptions exceeding 95 mg/kg/day were given and two of six were given in infants 3 months and younger. CONCLUSION: Many medical staff were unsure of current safe dosing regimens, particularly in the younger age groups. Seventeen percent of prescriptions were above 95 mg/kg/day although only 3% of children were given these doses due to on demand charting and due to audit by pharmacy and nursing staff. There are few guidelines for children 3 months and under. The literature suggests 60-65 mg/kg/day in infants 1-3 months, although this dose was only charted in 16% of prescriptions and phamacokinetic data favours a higher dose. In neonates 30 mg/kg/day achieves effective therapeutic concentrations but further studies are needed.