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Biomedical subjects

Peter Richardson

Publications and source records attributed to Peter Richardson.

26 records · Page 2Linked to original sources
PubMed2003

Association between hepatitis C infection and other infectious diseases: a case for targeted screening?

OBJECTIVE: Hepatitis C virus (HCV) shares risk factors and routes of transmission with several other infectious agents. However, the prevalence of comorbid infectious disorders among HCV-infected patients remains unknown. To analyze the association between HCV and several categories of infectious disorders, we carried out a case-control study using information from 172 hospitals contained in the computerized databases of the Department of Veterans Affairs. METHODS: We identified all HCV-infected patients who were hospitalized during 1992-1999. For each case, four control subjects without HCV were randomly chosen from hospitalized patients and were matched with cases on the year of admission. The frequencies of several predefined infectious disease diagnoses were compared between cases and control subjects, and the strength of these associations were assessed in multivariable logistic regression analyses. RESULTS: We identified 34,204 HCV-infected patients (cases) and 136,816 control subjects without HCV. Patients in the case group were younger (48.4 yr vs 59.8 yr), were more frequently nonwhite (38.5% vs 26.5%), and were more likely to have served in Vietnam (68.1% vs 33.0%); all p < 0.0001. Compared with control subjects, patients with HCV had a significantly higher prevalence of other blood-borne virus infections, including HIV (14.1% vs 3.0%) and hepatitis B (22.4% vs 0.7%); immunodeficiency-related infections, including cytomegalovirus (0.6% vs 0.2%), toxoplasmosis (0.3% vs 0.1%), cryptococcosis (0.4% vs 0.1%), and tuberculosis (3.3% vs 1.3%); sexually transmitted diseases, including gonococcus (0.5% vs 0.1%), chlamydia (1.6% vs 0.7%), syphilis (2.0% vs 0.6%), and genital herpes (1.0% vs 0.3%); and bacterial infection, including peritonitis, sepsis, endocarditis, cellulitis, and carbuncles (all p < 0.0001). After excluding potentially immunocompromised patients, including those with HIV, organ transplant, and cirrhosis, HCV remained significantly associated with CMV, cryptococcus, tuberculosis, and sexually transmitted diseases. Similar results were obtained when the analyses were restricted to Vietnam-era veterans. CONCLUSIONS: Several infectious diseases are more common among HCV-infected patients compared with those without HCV infection. These findings support an approach of targeted screening for HCV among patients with these infectious diseases.

Case-Control Studies↗
PubMed2003

Joint-specific multidimensional assessment of pain (J-MAP): factor structure, reliability, validity, and responsiveness in patients with knee osteoarthritis.

OBJECTIVE: To develop a reliable and valid instrument for measuring and monitoring joint-specific pain. METHODS: Developed using patient interviews, reviews of pain literature, and expert input from orthopedic surgeons, the final Joint-Specific Multidimensional Assessment of Pain (J-MAP) includes the 6-item Pain Sensory and the 4-item Pain Affect subscales. Scores on the J-MAP Pain Sensory and Affect subscales range from 0 to 100, with higher scores indicating more pain intensity and worse pain distastefulness, respectively. Following the assessment of the factor structure, patients' scores (n = 180) on the J-MAP subscales were converted to equal interval scores using Rasch analyses. A psychometric evaluation of the items and Rasch-calibrated scores was conducted and included an assessment of reliability, validity, and responsiveness for use with patients with radiographic knee osteoarthritis. RESULTS: Evidence from the factor analyses showed that the J-MAP Pain Sensory and Affect items made up 2 distinct factors. Internal consistency estimates for the J-MAP subscales exceeded 0.85. The J-MAP subscales showed evidence for validity and were shown to be internally and externally responsive, demonstrating greater responsiveness than the Arthritis Impact Measurement Scale or the Medical Outcome Study Short Form-36 pain subscales. Finally, evidence was found supporting the J-MAP subscales' ability to distinguish target joint pain from pain emanating from other musculoskeletal conditions. CONCLUSION: The J-MAP is a reliable, valid, and responsive measure for assessing joint-specific pain at a single time point, or changes over time for one or a group of patients with knee osteoarthritis. With this initial evidence of its psychometric rigor, further testing of the measurement properties of the J-MAP in other joints and in other populations should be undertaken.

Activities of Daily Living↗
PubMed2002

Prevention of complicated ulcer disease among chronic users of nonsteroidal anti-inflammatory drugs: the use of a nomogram in cost-effectiveness analysis.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with an increased risk of clinical upper gastrointestinal tract (UGI) events, namely, symptomatic ulcer, perforation, bleeding, and obstruction. Our objective in this study was to compare the cost-effectiveness of several strategies aimed at reducing the risk of clinical UGI events in NSAID users. METHODS: A decision tree model was used for patients requiring long-term treatment with NSAIDs to compare conventional NSAID therapy alone with 7 other treatment strategies to reduce the risk of NSAID-related clinical UGI events (cotherapy with proton-pump inhibitor, cotherapy with misoprostol, cyclooxygenase [COX]-2-selective NSAID therapy, or Helicobacter pylori treatment followed by each of the previous strategies, including conventional NSAID treatment, respectively). The outcome measure is the incremental cost per clinical UGI event prevented compared with conventional NSAID treatment over 1 year. RESULTS: The use of a COX-2-selective NSAID and cotherapy with proton-pump inhibitors were the 2 most cost-effective strategies. However, the incremental cost associated with these strategies was high (>$35 000) in persons with a low risk of clinical UGI event with conventional NSAIDs (eg, 2.5% per year). If the baseline risk of clinical UGI events is moderately high (eg, 6.5%), using a COX-2-selective NSAID becomes the most effective and least costly (dominant) treatment strategy, followed closely by cotherapy with a daily proton-pump inhibitor. Because small changes in costs or assumed efficacy of these drugs could change the conclusions, the incremental cost-effectiveness ratios between any 2 strategies were presented in a nomogram that allows the flexible use of a wide range of values for costs and rates of clinical UGI events. CONCLUSIONS: The risk of clinical UGI events in NSAID users depends on their baseline risk, the added risk associated with the individual NSAID, and the protection conferred by cotherapy. A nomogram can be used to incorporate these factors and derive estimates regarding cost-effectiveness of competing strategies aimed at reducing the risk of clinical UGI events.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Intravenous zoledronic acid in postmenopausal women with low bone mineral density.

BACKGROUND: Bisphosphonates are effective agents for the management of osteoporosis. Their low bioavailability and low potency necessitate frequent administration on an empty stomach, which may reduce compliance. Gastrointestinal intolerance limits maximal dosing. Although intermittent intravenous treatments have been used, the optimal doses and dosing interval have not been systematically explored. METHODS: We studied the effects of five regimens of zoledronic acid, the most potent bisphosphonate, on bone turnover and density in 351 postmenopausal women with low bone mineral density in a one-year, randomized, double-blind, placebo-controlled trial. Women received placebo or intravenous zoledronic acid in doses of 0.25 mg, 0.5 mg, or 1 mg at three-month intervals. In addition, one group received a total annual dose of 4 mg as a single dose, and another received two doses of 2 mg each, six months apart. Lumbar-spine bone mineral density was the primary end point. RESULTS: There were similar increases in bone mineral density in all the zoledronic acid groups to values for the spine that were 4.3 to 5.1 percent higher than those in the placebo group (P<0.001) and values for the femoral neck that were 3.1 to 3.5 percent higher than those in the placebo group (P<0.001). Biochemical markers of bone resorption were significantly suppressed throughout the study in all zoledronic acid groups. Myalgia and pyrexia occurred more commonly in the zoledronic acid groups, but treatment-related dropout rates were similar to that in the placebo group. CONCLUSIONS: Zoledronic acid infusions given at intervals of up to one year produce effects on bone turnover and bone density as great as those achieved with daily oral dosing with bisphosphonates with proven efficacy against fractures, suggesting that an annual infusion of zoledronic acid might be an effective treatment for postmenopausal osteoporosis.

Aged↗
PubMed2002

Psychiatric disorders among veterans with hepatitis C infection.

BACKGROUND & AIMS: The presence of psychiatric, drug-, and alcohol-use disorders in hepatitis C virus (HCV)-infected patients may influence their management and prognosis. The frequency and the risk for these disorders among HCV-infected patients are unknown. METHODS: We identified all HCV-infected veteran patients who were hospitalized during 1992-1999 and searched the inpatient and outpatient computerized files for predefined psychiatric, drug-, and/or alcohol-use disorders. We then performed a case-control study among Vietnam veterans; controls without HCV were randomly chosen from hospitalized patients. RESULTS: We identified 33,824 HCV-infected patients, in whom 86.4% had at least one past or present psychiatric, drug-, or alcohol-use disorder recorded. However, only 31% had active disorders as defined by hospitalization to psychiatric or drug-detoxification bed sections. There were 22,341 HCV-infected patients from the Vietnam period of service (cases) who were compared with 43,267 patients without HCV (controls). Cases were more likely to have depressive disorders (49.5% vs. 39.1%), posttraumatic stress disorder (PTSD) (33.5% vs. 24.5%), psychosis (23.7% vs. 20.9%), bipolar disorder (16.0% vs. 12.6%), anxiety disorders (40.8% vs. 32.9%), alcohol (77.6% vs. 45.0%), and drug-use disorders (69.4% vs. 31.1%). In multivariable regression analyses that adjust for age, sex, and ethnicity, drug use, alcohol-use, depression, PTSD, and anxiety remained strongly associated with HCV. CONCLUSIONS: Several psychiatric, drug-, and alcohol-use disorders are commonly found among HCV-infected veterans compared with those who are not infected. At least one third of these patients have active disorders. A multidisciplinary approach to the management of HCV-infected patients is needed.

Adult↗