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Biomedical subjects

Ken Bassett

Publications and source records attributed to Ken Bassett.

15 recordsLinked to original sources

Changes in rates of upper gastrointestinal hemorrhage after the introduction of cyclooxygenase-2 inhibitors in British Columbia and Ontario.

BACKGROUND: Population rates of upper gastrointestinal (GI) hemorrhage have been observed to increase with the introduction and rapid uptake of selective cyclooxygenase-2 (COX-2) inhibitors. Changes in COX-2 inhibitor use and upper GI bleeding rates in regions with relatively restrictive drug policies (e.g., British Columbia) have not been compared with changes in regions with relatively less restrictive drug policies (e.g., Ontario). METHODS: We collected administrative data for about 1.4 million people aged 66 years and older in British Columbia and Ontario for the period January 1996 to November 2002. We examined temporal changes in the prevalence of NSAID use and admissions to hospital because of upper GI hemorrhage in both provinces using cross-sectional time series analysis. RESULTS: During the period studied, the prevalence of NSAID use in British Columbia's population of older people increased by 25% (from 8.7% to 10.9%; p < 0.01), as compared with a 51% increase in Ontario (from 10.9% to 16.5%; p < 0.01). Hospital admissions because of upper GI hemorrhage increased significantly in Ontario by about 16% on average, or about 2 admissions per 10 000 elderly people, above expected values (p < 0.01). A similar increase was not observed in British Columbia. INTERPRETATION: More restrictive drug coverage policies, although limiting access to drugs and their potential benefits, may protect the population from adverse drug effects.

Aged↗

Case selection for statins was similar in two Canadian provinces: BC and Ontario.

OBJECTIVES: Though statins are fully reimbursed by the public drug programs for seniors in British Columbia (BC) and Ontario, Canada, population-based rates of statin prescription are markedly higher in Ontario. We aimed to assess whether new statin users in BC and Ontario differ in terms of their risk for future coronary heart disease (CHD) events. STUDY DESIGN AND SETTING: We collected information for 1998-2001 on demographics, outpatient prescriptions, physician visits, hospital admissions, and vital status from administrative databases to compare the proportions of new statin users aged 66 years and older who had evidence of an acute coronary syndrome (ACS), chronic CHD, neither ACS nor CHD but diabetes, or none of the above. RESULTS: Approximately 15% and 20% of BC and Ontario seniors, respectively, had filled a statin prescription by 2001. Among new statin users in the two provinces, virtually identical proportions had evidence of ACS (8%), chronic CHD (25%), and diabetes (14%), for an overall proportion of roughly 50% at high risk for CHD events. CONCLUSION: New statin users in BC and Ontario were at similar risk for future CHD events. Poorer case selection is unlikely to explain the relatively higher rates of statin prescription in Ontario.

Aged↗

Awareness of eye diseases and risk factors: identifying needs for health education and promotion in Canada.

BACKGROUND: Little is known about the level of general public knowledge in Canada regarding the risk factors, prevention, and treatment of major blinding eye diseases. METHODS: The study was a cross-sectional survey using self-administered questionnaires of patients presenting to 33 family practitioners' offices in British Columbia. We asked patients' opinions on the "value" of preventing blindness; the possibility of preventing cataract, glaucoma, and macular degeneration; the possibility of treating these conditions; and their knowledge of risk factors. RESULTS: A total of 882 adults completed the questionnaires. Preventing vision loss was reported as one of 2 top health priorities in 28% of the questionnaires, more commonly by those with higher education and non-European ancestry. Overall, 69.2% reported familiarity with cataract as a cause of vision loss, 41.2% with glaucoma, and 20.2% with macular degeneration. Of these, 97.5% recognized the possibility of treatment for cataract, 91.5% for glaucoma, and 77.0% for macular degeneration, yet few respondents knew risk factors (amenable to intervention) for specific eye diseases. Men and younger respondents were more likely to report not knowing risk factors. Chinese-Canadians were least familiar with the association between smoking and cataract. Family history, probably the most important factor to help diagnose glaucoma, was recognized by only 23% of respondents. INTERPRETATION: Although loss of vision was reported as a major medical concern, there is little understanding of the risk factors for different eye diseases. The association of non-European ancestry and low educational attainment with poor knowledge of eye diseases suggests that innovative education programmes in primary and secondary schools and in non-English languages are needed to improve knowledge, attitudes, and practices.

Adult↗

RESIO revisited: visual function assessment and cataract surgery in British Columbia.

BACKGROUND: Cataract surgery in a population with mild levels of functional impairment was studied in the Regional Evaluation of Surgical Indications and Outcomes (RESIO) project. The RESIO investigators assessed the overall visual function assessment (VFA) score before and after surgery. In this study we reanalysed available RESIO data to better understand the findings for individual VFA items in this patient population. METHODS: We calculated effect sizes for longitudinal changes in each VFA item and for changes in overall VFA scores using the Mann-Whitney statistic. We considered effect sizes less than 0.3 as small, between 0.3 and 0.8 as moderate, and more than 0.8 as large. We compared differences in the individual VFA item scores before and after cataract surgery using a paired t test and Wilcoxon's signed-rank test. RESULTS: Of the 32 surgeons originally involved in the RESIO project, 18 (60%) agreed to have the data for their patients reanalysed. We found pre- and postoperative VFA data for 709 cataract operations (mean age of patients 73.4 years [standard deviation 9.4 years]; 60.7% women). Of the 47 people with a perfect preoperative VFA score, 28 (59.6%) had a perfect score postoperatively, 13 (27.6%) had a score of 90 or better, 5 (10.6%) had a score of 87 to 90, and 1 (2.1%) had a score of 67. Among the 200 people with a preoperative VFA score of 90 to 99, postoperatively the VFA score improved for 146 (73.0%), remained the same for 43 (21.5%) and worsened for 11 (5.5%). The mean scores for all individual VFA items improved postoperatively. The largest improvements were noted for "driving during the day" (effect size 1.1), "self-care activities" (0.8), "driving during the night" (0.5), "doing fine handiwork" (0.5), "reading newspaper or book" (0.4) and "participating in religious activities" (0.4). INTERPRETATION: The original conclusion from the RESIO project seems correct: based on VFA, the current threshold for cataract surgery in British Columbia is very low. Individual VFA items, particularly reading and night driving, are most strongly and consistently influenced by cataract surgery, regardless of overall VFA score. In the absence of visual acuity data, it is not possible to relate VFA to cataract surgical decision-making in British Columbia.

Activities of Daily Living↗

Cataract surgical outcome at the Vancouver Eye Care Centre: can it be predicted using current data?

BACKGROUND: Patients selected for cataract surgery have an increasingly wider range of coexisting ocular and systemic diseases. The aim of this study was to determine whether preoperative patient characteristics can assist surgeons in identifying patients who are at increased risk of having little or no improvement in visual outcome after cataract surgery. METHODS: We prospectively studied a randomly selected subset (20%) of patients with cataract undergoing cataract extraction at a tertiary centre in Vancouver. There were no patient exclusion criteria. Pre-, intra- and postoperative clinical data were collected from medical records. RESULTS: We studied 1329 cataract surgical procedures from March 1999 to December 2000. Of the 1329, 851 had complete pre- and postoperative visual acuity data. The mean age of the 851 patients was 73.2 (standard deviation 10.6) years, 575 (67.6%) were women, and 472 procedures (55.5%) were first-eye procedures. Preoperatively, the best-corrected visual acuity was 20/40 or better in 146 eyes (17.2%), 20/50 in 173 (20.3%), 20/60 to 20/70 in 248 (29.1%), and 20/80 or worse in 284 (33.4%). Almost half of the patients (419 [49.2%]) had at least one coexisting eye disease in the operated eye. At about 3 months postoperatively, the best-corrected visual acuity had improved in 786 eyes (92.4%), remained the same in 42 (4.9%) and had worsened in 23 (2.7%). Of the 23 eyes with worse visual acuity, half had preoperative visual acuity of 20/40 or better; most of the remaining eyes had preoperative vision of 20/50 to 20/70. Of the 42 eyes with unchanged vision, 22 (52%) had preoperative visual acuity worse than 20/100; the remaining eyes were distributed across the visual acuity range. An increase of 1 year of age increased the odds of having a poor visual acuity outcome by 2% to 4%. Worse preoperative visual acuity predicted an increased likelihood of a poor outcome; this effect increased sharply for eyes with preoperative visual acuity of 20/80 or worse. After adjustment for age and preoperative visual acuity, patients with three or more coexisting eye diseases in the operated eye were 10 to 24 times more likely to have the worst postoperative visual acuity. INTERPRETATION: The presence and number of coexisting ocular diseases, increased age and poor preoperative visual acuity predicted an unchanged or worse visual acuity after cataract surgery.

Aged↗

Improving population health or the population itself? Health technology assessment and our genetic future.

The province of British Columbia (BC), Canada is developing its first population-wide prenatal genetic screening program, known as triple-marker screening (TMS). TMS, initiated with a simple blood test, is most commonly used to screen for fetuses with the chromosomal abnormality known as Down syndrome or neural tube disorders. Women testing TMS-positive are offered diagnostic amniocentesis and, if the diagnosis is confirmed, selective second-trimester abortion. The project described in this study was initiated to address the broad range of issues arising from this testing technology and provides an example of the new type of health technology assessment (HTA) contribution emerging (and likely to become increasing necessary) in health policy development. With the advent of prenatal genetic screening programs, would-be parents gain the promise of identifying target conditions and, hence, the option of selective abortion of affected fetuses. There is considerable awareness that these developments pose challenges in every dimension (ethical, political, economic, and clinical) of the health-care environment. In the effort to construct an appropriate prenatal screening policy, therefore, administrators have understandably sought guidance from within the field of HTA. The report authors concluded that, within the restricted path open to it, the role of government is relatively clear. It has the responsibility to maintain equal access to prenatal testing, as to any other health service. It should also require maintenance of medical standards and evaluation of program performance. At the same time, policy-makers need actively to support those individuals born with disabilities and their families.

British Columbia↗

How does direct-to-consumer advertising (DTCA) affect prescribing? A survey in primary care environments with and without legal DTCA.

BACKGROUND: Direct-to-consumer advertising (DTCA) of prescription drugs has increased rapidly in the United States during the last decade, yet little is known about its effects on prescribing decisions in primary care. We compared prescribing decisions in a US setting with legal DTCA and a Canadian setting where DTCA of prescription drugs is illegal, but some cross-border exposure occurs. METHODS: We recruited primary care physicians working in Sacramento, California, and Vancouver, British Columbia, and their group practice partners to participate in the study. On pre- selected days, patients aged 18 years or more completed a questionnaire before seeing their physician. We asked these patients' physicians to complete a brief questionnaire immediately following the selected patient visit. By pairing individual patient and physician responses, we determined how many patients had been exposed to some form of DTCA, the frequency of patients' requests for prescriptions for advertised medicines and the frequency of prescriptions that were stimulated by the patients' requests. We measured physicians' confidence in treatment choice for each new prescription by asking them whether they would prescribe this drug to a patient with the same condition. RESULTS: Seventy-eight physicians (Sacramento n = 38, Vancouver n = 40) and 1431 adult patients (Sacramento n = 683, Vancouver n = 748), or 61% of patients who consulted participating physicians on pre-set days, participated in the survey. Exposure to DTCA was higher in Sacramento, although 87.4% of Vancouver patients had seen prescription drug advertisements. Of the Sacramento patients, 7.2% requested advertised drugs as opposed to 3.3% in Vancouver (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.2-4.1). Patients with higher self- reported exposure to advertising, conditions that were potentially treatable by advertised drugs, and/or greater reliance on advertising requested more advertised medicines. Physicians fulfilled most requests for DTCA drugs (for 72% of patients in Vancouver and 78% in Sacramento); this difference was not statistically significant. Patients who requested DTCA drugs were much more likely to receive 1 or more new prescriptions (for requested drugs or alternatives) than those who did not request DTCA drugs (OR 16.9, 95% CI 7.5-38.2). Physicians judged 50.0% of new prescriptions for requested DTCA drugs to be only "possible" or "unlikely" choices for other similar patients, as compared with 12.4% of new prescriptions not requested by patients (p < 0.001). INTERPRETATION: Our results suggest that more advertising leads to more requests for advertised medicines, and more prescriptions. If DTCA opens a conversation between patients and physicians, that conversation is highly likely to end with a prescription, often despite physician ambivalence about treatment choice.

Adult↗

Cataract surgery at the Vancouver Eye Care Centre: do patient indications meet provincial clinical practice guidelines?

BACKGROUND: Cataract surgery, already the most common elective surgical procedure among patients over the age of 65 in North America, is rising in volume, because the population is aging while at the same time holding growing expectations of continued vitality. In meeting the need, there is a public interest in ensuring that cataract surgery is used appropriately. The purpose of this paper was to investigate the indication for cataract surgery performed in adults at a large tertiary care centre in Vancouver and to determine the extent to which patient criteria met the guidelines of the College of Physicians & Surgeons of British Columbia. METHODS: Patients attending the centre were enrolled in the cataract outcome assessment program through systematic sampling that included every patient with a personal health card number ending in 5 or 8 (20% of patients). There were no patient exclusion criteria. Pre-, intra- and postoperative clinical information was collected from patients' medical records. Patients were also sent a pre- and postoperative visual function and quality-of-life questionnaire. RESULTS: A total of 1098 cataract surgery procedures were performed in 896 patients from March 1999 to December 2000. The average age of the patients was 72.9 years; most (69.5%) were women. Just over half of the procedures (620 [56.6%]) were performed as first-eye surgery. In 191 cases (17.9%) the preoperative visual acuity was 20/40 or better in the affected eye. In most cases (82.1%) visual acuity of 20/50 or worse was the indication for surgery. In 89 cases (8.3%) there was not enough information in the chart to justify the surgery. INTERPRETATION: By examining standard information provided in patients' medical records, we were able to determine the indication for cataract surgery in 92% of cases. The most common indication was poor visual acuity.

Aged↗

Is there evidence for early mobilization following an extraarticular hand fracture?

The authors conducted a systematic review to determine if there is scientifically valid (level I or II) evidence for the effect of early motion (<21 days) of joints surrounding an extraarticular hand fracture on fracture healing or functional outcomes. Two reviewers independently evaluated for study inclusion, trial quality and internal validity. Six poor-quality, quasirandomized studies (level III evidence) involving 459 patients were included. Findings suggest that in simple, closed metacarpal fractures, early motion (EM) has the potential to: (1) result in earlier recovery of mobility and strength, (2) facilitate an earlier return to work, and (3) not affect fracture alignment. Findings also indicate that skin pressure problems are not associated with custom-molded metacarpal fracture braces. The scientific validity of EM interventions after an extraarticular hand fracture has not been established in well-conducted, randomized, controlled trials (level I or II evidence). Current evidence does not support or refute the use of EM after an extraarticular hand fracture. However, further investigations are warranted, as findings to date show a consistent potential for benefit with no significant risk of harm when early regional joint motions are incorporated into the management of closed, extraarticular, finger metacarpal fractures.

Early Ambulation↗

Outcomes-based drug coverage in British Columbia.

For the past decade the provincial drug plan in British Columbia has based the allocation of public subsidy on scientific standards of evidence. Coverage policies under B.C. PharmaCare are marked by the restriction of public subsidy until manufacturers provide valid evidence of a comparative health outcome advantage versus therapeutic alternatives. Implementing and maintaining such outcomes-based coverage policies has required a system of evidentiary review and support. Since 1994 the Therapeutics Initiative at the University of British Columbia has provided provincial decisionmakers with such support. We describe lessons from the B.C. experience for jurisdictions interested in basing coverage on evidence of proven comparative advantage for patients' health.

British Columbia↗

Using pharmacoepidemiology to inform drug coverage policy: initial lessons from a two-province collaborative.

Prescription drug plan managers seek "real-world" evidence regarding the safety and effectiveness of drugs and drug coverage policies. University-based pharmacoepidemiologists with access to administrative health data can help meet these information needs and, by collaborating with other health plans, exploit variations in plan policy. Canada, with its universal health insurance, public drug benefit plans, and population-based linked health care databases, is an ideal setting for such research. Here we describe our initial experience in collaborating with researchers and drug plan managers in British Columbia and Ontario.

British Columbia↗