1,721,016 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A longitudinal study of the usage of acid reducing medicine using a medicine claims database
No full textThesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2008.Acid-related disorders are common, chronic conditions that have considerable impact on a patient's quality of life. In a study conducted by Majumdar et al. (2003:2411) the prevalence of chronic acid-related disorders was 2.3%. Acid-related disorders represent a major financial consideration with respect to the costs of drug prescribing (Whitaker, 1998:6). Health care cost increases each year. This leads to an increased interest in economic evaluation of health care and medical technologies (Anell & Svarvar, 2000:175). Health care providers no longer make treatment decisions independent of the consideration of the resultant cost. The treatment provided must not only provide value but the value must be documented to justify spending money. Economic evaluation research has emerged to offer guidance to policy makers, practitioners, health plans and institutions facing difficult treatment and coverage decisions (Ellis era/., 2002:271).
The main objectives of this study were to investigate the prescribing patterns and cost of acid reducing medicine with special reference to proton pump inhibitors and histamine-2 receptor antagonists in a section of the private health care sector of South Africa from 2001 to 2006. A longitudinal retrospective drug utilisation study was done on acid reducing medicine items claimed through a national medicine claims database. The five study years were 2001, 2002, 2004, 2005 and 2006. All the study years stretched from 1 January to 31 December.
It was determined that acid reducing medicine items prescribed decreased from 2.74% during 2001 to 2.50% during 2006 of all medicine items claimed. The same decreasing trend was observed regarding the cost of acid reducing medicine items. The cost percentage decreased from 4.89% (2001) to 3.72% (2006). However, the average cost per medicine item for the acid reducers increased by 5.35% from 2001 (R230.04 ± 176.29) to 2002 (R243.72 ± 184.18) and then decreased by 15.23% from 2002 to 2004. It again decreased with 15.05% from 2004 (R206.19 ± 179.42) to 2006 (R175.70 ± 172.55). The changes in the average cost of acid reducers were of no practical significance. Proton pump inhibitors represented about half of the acid reducing medicine items prescribed and more than 70% of the total cost of acid reducing medicine items during the study years. The average cost of PPIs revealed a practical significant decrease (d > 0.8) from 2002 (R372.42 ± 156.62) to 2006 (R241.56 ± 177.21). H2RAs contributed between 15.00% and 18.26% of all acid reducing medicine items while contributing to between 9.68% and 16.85% of the total cost of all acid reducers. The active ingredient most often prescribed was lansoprazole during 2001 and 2002, esomeprazole during 2004 and omeprazole during 2005 and 2006. Lanzor® 30mg was the acid reducer with the highest cost from 2001 to 2005, while Pariet® 20mg took the lead in 2006. Zantac® 150mg effervescent tablets were the H2RA, with the highest cost, during the five study years. The percentage innovator items decreased by 4.50% from 2001 to 2002, increased by 1.01% from 2002 to 2004 and decreased again by 31.06% from 2004 to 2006. The slight increase in the percentage innovator medicine items claimed from 2002 to 2004 may be explained by the introduction of Nexiam® (esomeprazole) into the market in 2002. The total number of generic medicine items claimed contributed between 9.62% (n = R1 788 242.25) in 2001 and 30.75% (n = R3 196 163.34) in 2006 of the total cost of acid reducing medicine items. The average cost per day of innovator medicine items was higher than the average cost per day of generic medicine items. This might be explained by a lower average cost for generic medicine items. It was also determined that the prevalence of the two-drug regimens was the highest during the five study years. The Helicobacter pylori (H.pylori) eradication treatments, which included different antibiotics, increased from 2.72% in 2001 to 5.05% in 2006. The PDD for most of the active ingredients of H2RAs and PPIs remained stable during the study years. However, it appears that the PDDs, of the PPIs, active ingredients were more constant than the PDDs, or the H2RAs, active ingredients. The median of the different PPI active ingredients was reasonably more constant than the median of the different H2RA active ingredients. Thus the changes between the PPIs' and H2RAs' active ingredients might be explained by the variation in the median (the number of days the relevant medicine item was claimed for). It is then also recommended that the aspects of generic substitution as well as the usage of H2RAs as prescribed vs. self medication should be further investigated to increase possible cost savings.Master
A retrospective analysis of the prescribing patterns of hipolipidaemic drugs : a pharmacoeconomic approach
Get PDFThesis (M.Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2010.Background: More than 5.5 million South Africans aged 30 years and older are at risk of chronic disease by virtue of their triglyceride levels (Maritz, 2006:101). Dyslipidaemia is common in westernized and industrialized communities (Steyn et al., 2000:720), especially so for South Africa, where burden of disease data show dyslipidaemia to be the second most prevalent of all the chronic conditions in the country (Council for Medical Schemes, 2006:48). It is therefore no surprise that at 3.3 per cent hipolipidaemics ranked second highest based on prevalence percentage per therapeutic group in the 2005 Mediscor medicines review on South African medical claims data (Bester et al., 2005:8-11). Hipolipidaemic drugs subsequently also ranked second highest for expenditure per therapeutic group, achieving a total expenditure of 5.8 per cent. Objective: The purpose of this study was to characterise the usage and cost of hipolipidaemic drugs in the private health care environment in South Africa based on various categories, including age, sex, prescriber type and generic indicator.
Methods: A quantitative retrospective drug utilisation review was performed using dispensing records from a medicine claims database. Data for a two-year period (1 Jan. 2005 to 31 Dec. 2006) were used. Hipolipidaemic medicine usage was analysed according to five patient age strata: patients younger than 9 years, 10 ≤ 19 years, 20 ≤ 45 years, 46 ≤ 59 years and older than 59 years. Basic descriptive statistics such as frequencies and arithmetic mean (average) were used to characterise the study sample, and were calculated using the Statistical Analysis System (SAS®) for Windows 9.1® program (SAS Institute Inc., 2002-2003). Results: The database consisted of 19 860 593 and 21 473 062 medicine item claims for 2005 and 2006 respectively, at a total cost of R 1 893 376 921.00 (for 2005) and R2 046 944 383.00 (for 2006). Patients receiving hipolipidaemic medicine items represented about 7.2% of the total number of patients on the database in both 2005 and 2006. About 47% of the study population in both 2005 and 2006 was female, compared to 53% males. Hipolipidaemics represented between 3.1% (N = 19 860 593) and 3.3% (N = 21 473 062) of the total number of items claimed during the study period. The total cost of hipolipidaemics accounted for between 5.6% (N = R1 893 376 921.00) and 5.8% (N = R2 046 944 383.00) of the total cost of all medications claimed during the study period. The average cost per item of hipolipidaemics was R170.63 ± 70.19 in 2005 compared to R167.08 ± 71.93) in 2006. HMG-CoA reductase inhibitors formed the leading therapeutic class in hipolipidaemic medicine items in all age groups on the database, except for children aged 0 ≤ 9 years, where the “others” group, in particular cholestyramine (Questran Lite 4 mg) was claimed more frequently. Of the items claimed for both study periods, simvastatin was the most commonly claimed, accounting for 45.35% (n = 284 232) and 46.21% (n = 325 970) respectively of the number of hipolipidaemic items claimed, at a total cost of 30.97% (n = R33 119 294.18) and 31.38% (n = R36 983 938.41) for 2005 and 2006 respectively. Non-substitutable and generic hipolipidaemic medicine items carried the largest percentage of prevalence and cost in both study periods for both sex categories and all age groups. The majority of claims for hipolipidaemic medicine items were prescribed by general medical practitioners, followed by “other prescribers” and then by cardiologists. Only a small number of prescriptions claimed were prescribed by thoracic surgeons and even fewer by pharmacotherapists and pharmacists. Trade name products that were mostly prescribed were Lipitor and Adco-Simvastatin. Of all the hipolipidaemic drugs utilised on the database, only three active ingredients (bezafibrate, simvastatin and pravastatin) had generic equivalents available at the time of the study. With total substitution (100%) of these three drugs with the average price of the available generic hipolipidaemic equivalents on the database, a cost saving of R1 744 462.27 or 1.63% (N = R106 943 348.53) was possible in 2005. In 2006, a total cost saving of R1 526 985.79 or 1.30% (N = R117 862 631.87) was calculated.
Conclusion: The study highlighted the most commonly prescribed hipolipidaemics within a sub-population of South African patients. The high average cost per prescription of hipolipidaemic drugs indicates that they are relatively expensive in comparison to other medications. Generic (and therapeutic) substitution should be investigated as potential cost-saving mechanisms in the private health care sector of South Africa.Master
Assessment of adverse drug reactions caused by HAART at antiretroviral clinics in the Maseru district, Lesotho
Get PDFMPham (Pharmacy Practice), North-West University, Potchefstroom Campus, 2014Antiretroviral drugs are successful in controlling HIV/AIDS and reducing disease progression. Antiretroviral regimens are stopped in up to 25% of all patients during their initial treatment therapy as a result of adverse drug effects, failing treatment and nonadherence within the initial eight months of treatment (Sharma et al., 2007: 235). A pharmacovigilance surveillance system makes it possible for physicians, pharmacists and other healthcare providers to report suspected ADRs. The purpose of this system is to operate as a guide in identification of new ADRs and predisposing risk factors to known ADRs. The objective of this study was to assess the prevalence and documentation of adverse drug reactions (ADR) in the private and public antiretroviral clinics in Maseru district, with special reference to zidovudine (AZT) and tenofovir (TDF) - based regimens. The empirical investigation was divided into two phases. The first phase was a cross-sectional quantitative retrospective drug utilisation review study which focused on the occurrence of adverse drug reactions in patients taking zidovudine (AZT) and tenofovir (TDF). The second phase, a survey in a form of questionnaires for the health professionals. Drug utilisation review: The sample size of patients was 300. Of the 44 patients who experience ADRs, 72.73% (n = 32) were female and 27.27% (n = 12) were male. A greater number of patients who experienced ADRs were females with 43.18% (n = 19) presenting with skin rash, 27.27% (n = 12) with nausea/vomiting, and 2.27% (n = 1) with diarrhoea. In male patients, 2.27% (n = 1) had peripheral neuropathy, 18.18% (n = 8) skin rash, 2.27% (n = 1) Fanconi syndrome, 2.27% (n = 1) nausea/vomiting, and 2.27% (n = 1) diarrhoea. Patients whose ART regimen changed due to ADRs were five. 60% (n = 3) of the patients were females and 40% (n = 2) were males. There was an estimated increase of 0.0025 cell/mm³, 0.0026 cell/mm³, 0.0024 cell/mm³, 0.0025 cell/mm³, and of 0.0019 cell/mm³ in CD4 cell count per day according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. An estimated increase of 0.00021 g/dL, 0.00022 g/dL, 0.00018 g/dL, 0.00022 g/dL, and of 0.00020 g/dL in Hb profile per day occurred according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. There was an estimated increase of 0.000062%, 0.000046%, 0.000068%, 0.000062%, and of 0.00017% in neutrophil count according to sex, age group, weight group, initial ART regimen, and ADRs per day, respectively. There was an estimated increase of 0.000044 IU/L, 0.000043 IU/L, 0.000046 IU/L, and of 0.000028 IU/L in ALT according to sex, age group, weight group, and initial ART regimen per day, respectively. An estimated decrease of 0.000013 IU/L in ALT according to ADRs per day also occurred. There was an estimated decrease of 0.00038 μmol/L, 0.00039 μmol/L, 0.00040 μmol/L, 0.00040 μmol/L, and of 0.00028 μmol/L in serum creatinine per day according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. There was an estimated decline of 0.00023 mmol/L, 0.00022 mmol/L, 0.00023 mmol/L, 0.00024 mmol/L, and of 0.00015 mmol/L per day in urea according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. Health professional’s questionnaire: 49 health professionals responded to the questionnaire. 100% (n= 49) of the participants showed that they did not use the yellow card scheme to report ADRs. 34.65% (n = 17) use the individual case safety reports. 57.14% (n = 28) used the structured databases to report ADRs. 85.71% (n = 42) documented in the patient bukana, and 6.12% (n = 3) used the HIV/AIDS ART card to document ADRs occurrence. 91.84% (n = 45) of the health professionals never filled the ADR reporting form in their working environment. In conclusion, adverse drug reactions occurring in a hospital or healthcare facility should be recorded and reported by the medical practitioners, nurses, pharmacists, and the pharmacy technicians. Therefore, it is important to assess the continuous evaluation of the benefits and harm of medicines which will help in achieving the ultimate goal of making safer and more effective treatment available for patients. As well as to help the health professionals to participate in the very important process of continuous surveillance of safety and efficacy of pharmaceutical products used in clinical practice.Master
Overview of antidepressant usage and cost 2004 until 2006
No full textThesis (M. Pharm.)--North-West University, Potchefstroom Campus, 2008.Depression has an increasingly significant economic impact and quality of life burden on patients, employers and third party payers worldwide (Hylan et a/., 1998:53). Current projections indicate that the global burden of depression will rank second only to ischemic heart disease by the year 2020 (Hylan et a/., 1998:53). The prevalence of clinical depression in South Africa has been reported to range between 14 to 49 per cent of the general population (Triant, 2002:21). The cost of mental disorders in South Africa particularly when they are diagnosed late, are at least as high as R5 billion each year (The mental health information centre, 2002). According to the report of Mediscor medicines review for the year 2006 (Bester & Hammann, 2007) antidepressants contributed up to 5.0 per cent of the total medicine expenditure and was ranked third according to total medicine expenditure.
The objective of this study was to review the prescribing patterns and cost of antidepressants in a section of the private health care sector of South Africa by using a medicine claims database for the years 2004 to 2006. A retrospective drug utilisation study was done on data provided by the database of a pharmaceutical benefit management (PBM) company. The cost savings attributable to generic substitution were calculated by means of a cost minimisation study. Comparisons and analyses were done for 2004 to 2006, using the Statistical Analysis System (SAS for Windows, 9.1, 2002-2003). Results of the study showed that antidepressant prescriptions accounted for 5.66% (n = 2 595 242), 5.05% (n = 1 621 739) and 4.51% (n = 996 787) of all prescriptions claimed during 2004, 2005 and 2006 respectively. The total cost for antidepressants for 2004 amounted to R 32 199 165.09; making depression the third most costly condition during 2004. During 2005 and 2006, these costs were ranked sixth and seventh respectively amongst all pharmacological classes on the database. Prescriptions of antidepressants to female patients represented 42.26% (n = 44 915) compared to 17.86% prescribed to male patients. Antidepressant prescriptions ranked the highest for the age group older than 19 and younger than 44 years of age with a percentage of 42.72% of all prescriptions (n = 44 915); followed by antidepressant prescriptions for the age group older than 44 and younger than 59 years of age with a percentage of 35.06% (n = 44 915). The most prevalent pharmacological category was the selective serotonin reuptake inhibitors (SSRIs) followed by tricyclic antidepressants. The most common prescribed antidepressants for
2004 was fluoxetine (18.87%, n = 157 810) while amitriptyline was the drug of choice during 2005 (19.11%, n = 86 521) and 2006 (20.09%, n = 47 740). Drug interactions with a significance rating of one and two according to Tatro (2002: xiv), were respectively 79.45% (n = 5 247) in 2004, 65.76% (n = 2 415) in 2005 and 51.56% (n = 1 470) in 2006. Generic antidepressants represented 58.67% (n = 157 810) of all prescriptions in its class in 2004, compared to 56.49% (n = 86 521) in 2005 and 63.30% (n = 47 470) in 2006. It was finally determined that the PBM company could have saved up to 10.87% (n = R 56 183 697.91) on mental health care cost during the study period if all innovator products on the database had been substituted with the least expensive generic product.
Recommendations for future research in this field were also made.Master
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A drug utilisation review of the concept of metabolic syndrome using a South African medicines claims database
Get PDFThesis (PhD (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2012.The aim of the study was to determine the prevalence, medicine prescribing patterns and direct treatment cost associated with the metabolic syndrome and its components in the private health care sector of South Africa. A two–dimensional research method was employed, consisting of a literature review and an empirical investigation. The objective of the literature review was to provide background to the study by conceptualising the metabolic syndrome and the components forming part thereof. The empirical investigation consisted of a descriptive, quantitative, retrospective drug utilisation review study, utilising medicine claims data sourced from a South African Pharmaceutical Benefit Management (PBM) company for the period January 1, 2005 to December 31, 2008. Data for a total 246 122 patients from 2005, 252 080 from 2006, 208 632 from 2007 and 196 242 from 2008, receiving at least one medicine item from the pharmacological medicine classes of antihypertensives (including diuretics, MIMS® classifications 7.3 and 16.1), hipolipidaemics (MIMS® classification 7.7) and antidiabetics (MIMS® classification 19.1) were analysed. Metabolic syndrome was defined according to the American Heart Association/National Heart, Lung and Blood Institute criteria, as patients with claims for 1 medicine item(s) per year from each of these drug classes. Seventy one per cent (n = 261 036) of patients from 2005 met one risk selection criterion for the metabolic syndrome, compared with 69.9% from 2006 (n = 269 452), 66.6% (n = 226 264) from 2007 and 64.9% (n = 214 109) from 2008 (male:female ratio 1:1.5 for 2005–2008; age peak >45,60 year). A total 60 683 (4.0%, n = 1 509 621) of patients from the 2005 data set met at least two risk criteria for the metabolic syndrome. This number of patients increased to reach 63 835 (4.1%, n = 1 558 090) in 2006, thereafter decreasing to 57 992 (4.9%, n = 1 178 596) in 2007 and 57 220 (5.9%, n = 974 497) in 2008. A total 5.7% (n = 246 122) of patients in 2005 met inclusion criteria for the metabolic syndrome, increasing to 6.5% (n = 252 080) in 2006, 7.8% (n = 208 632) in 2007 and 8.3% (n = 196 242) in 2008 (male to female ratio for 2005 – 2008:1.2:1). In general, prevalence increased from ~0.1% of patients aged >0,15 years to ~0.3% in those >15,30 years, ~6% in patients >30,45 years, ~40% in patients aged >60,75 years and ~20% in patients >75 years. The average prevalent age appeared earlier in males than in females by 2 years. The average pill burden per prescription for patients from the 2005–metabolic syndrome category was 2.6 ± 1.43, compared with 2.6 ± 1.47 in 2006, 2.7 ± 1.52 in 2007 and 2.7 ± 1.53 in 2008, with a maximum of 16 items claimed per patient in 2005, 14 in 2006 and 2007, respectively and 19 in 2008. Antidiabetics, hipolipidaemics and antihypertensives were claimed in a ratio of 1:1:2 across the 4–year study period. A prescribing index of 20 medicine items (active substances) based on prescribing volume was established for metabolic syndrome patients; the 5 most claimed medicine items on this index was metformin, simvastatin, atorvastatin, insulin and gliclazide. A total of 17 716 different treatment regimens was identified for patients from the 2008–metabolic syndrome category, containing from one to 12 different active substances per regimen. Overall 90.7% (n = 17 716) of treatment regimens contained between 3 and 7 different active substances per prescription; a further 3.3% contained 8 active substances each. The combination of indapamide and perindopril with amlodipine, or simvastatin and/or metformin had the highest prevalence among those regimens containing 3 active substances. The total direct medicine treatment cost from the metabolic syndrome category amounted to R71.7 million in 2005, increasing to R94.7 million in 2008. Medical aid schemes contributed 90.0% (n = R71 724 445.88) towards these costs in 2005, decreasing to 86.0% (n = R94 690 393.54) in 2008. The average scheme contribution was R131.14 ± 135.64 (median R103.12) per medicine item in 2005, compared with R126.63 ± 133.65 (median R101.24) in 2006, R128.39 ± 141.69 (median R101.35) in 2007 and R122.45 ± 143.97 (median R94.27) in 2008. Patients paid the excess 10% (2005) to 14% (2008) of costs out–of–pocket for co–payments on medicine items at an average cost of R14.55 ± 34.26 (median R0.00) per item for 2005, compared with R15.80 ± 38.04 (median R0.00) during 2006, R16.61 ± 38.01 (median R0.00) in 2007 and R19.95 ± 40.06 (median R2.28) in 2008. The average annual direct medicine treatment cost for a patient from the metabolic syndrome category summed to R4 809.20 ± 4 057.46 (median R3 850.67) in 2005, compared with R5 053.34 ± 4 033.85 (median R4 041.16) in 2006, R5 503.88 ± 4 348.67 (median R4 357.79) in 2007 and R5 300.03 ± 4 433.93 (median R4 100.06) in 2008. A total 7 050 patients (39.5%, n = 17 866) or approximately every third patient from the metabolic syndrome category had at least one other Chronic Disease List (CDL) condition during 2008. An average chronic disease count of 1.4 ± 0.63 (median 1) (range: 1–5) per patient was calculated. Diseases that co–occurred most were hypothyroidism (22.7%, n = 7 050), coronary artery disease (13.6%, n = 7 050), cardiac failure (10.7%, n = 7 050), asthma (7.3%, n = 7 050) and glaucoma (4.5%, n = 7 050). In conclusion, this study established base–line estimates on the prevalence, medicine prescribing patterns and associated direct medicine treatment cost of patients with metabolic syndrome and/or those at risk for the development thereof in the private health care sector of South Africa, as defined by surrogate measures of criteria from the American Heart Association and National Blood Institute. Recommendations for future extensions and diversifications to the study were made.Doctora
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