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Biomedical subjects

M J Baker

Publications and source records attributed to M J Baker.

At least 19 recordsLinked to original sources
PubMed2006

Identifying differences in feed efficiency among group-fed cattle.

Identification of efficient animals in the postweaning growth phase for use in selection for improved feed efficiency is important to improve the economic and environmental sustainability of the beef cattle industry. Progeny testing using group-fed animals in commercial feedlots is the most common and practical method used to evaluate postweaning growth on large numbers of animals. We developed the Cornell Value Discovery System (CVDS) to dynamically predict growth rate, accumulated weight, days required to reach target body composition, carcass weight, and composition of individual beef cattle fed in group pens. Observed BW, ADG, BW at 28% empty body fat (EBF), breed type, environmental conditions, and dietary ME concentration are used by the CVDS to predict, for each animal in a pen, the feed DM required for maintenance (FFM), the feed DM required for gain, and the total DM required for maintenance and gain (DMR). The CVDS then computes DMR-to-ADG ratio (DMR:ADG), which is a feed conversion measure, and ADG-to-DMR ratio (ADG:DMR), which is a feed efficiency measure, for each animal. This study used the observed F:G ratio of 362 individually fed steers to evaluate CVDS-predicted indicators of feed efficiency and the Kleiber ratio. A subset of 37 data points was used to evaluate residual feed intake (RFI) as an indicator of feed efficiency. The database included 4 published studies, each with detailed individual animal description, environment, diet, and body composition information. The CVDS-predicted DMR:ADG accounted for 84% of the variation in the actual F:G ratio with a mean bias of 1.94% (P = 0.20). The predicted FFM to actual DMI ratio had a high correlation with actual ADG (R2 = 0.76), and indicated a decay-type nonlinear dilution of FFM as ADG increased. The CVDS-predicted ADG:DMR and the Kleiber ratio had a significant (R2 = 0.88) logarithmic relationship. In an analysis of a contemporary group within the database, RFI was highly correlated with the F:G ratio (r = 0.71). There was a positive relationship between RFI and EBF. The RFIM (DMI - DMR) was moderately correlated with DMI and ADG (0.37 and -0.38; respectively), suggesting that selecting for low RFI(M) would decrease DMI and increase ADG in this database. We conclude that the CVDS model can be used to identify differences in the F:G and G:F ratios by predicting DMR for individual growing cattle fed in groups.

Animal Feed↗
PubMed2006

Using ultrasound measurements to predict body composition of yearling bulls.

Carcass traits have been successfully used to determine body composition of steers. Body composition, in turn, has been used to predict energy content of ADG to compute feed requirements of individual animals fed in groups. This information is used in the Cornell value discovery system (CVDS) to predict DM required (DMR) for the observed animal performance. In this experiment, the prediction of individual DMR for the observed performance of group-fed yearling bulls was evaluated using energy content of gain, which was based on ultrasound measurements to estimate carcass traits and energy content of ADG. One hundred eighteen spring-born purebred and crossbred bulls (BW = 288 +/- 4.3 kg) were sorted visually into 3 marketing groups based on estimated days to reach USDA low Choice quality grade. The bulls were fed a common high-concentrate diet in 12 slatted-floor pens (9 to 10 head/pen). Ultrasound measurements including back-fat (uBF), rump fat, LM area (uLMA), and intramuscular fat were taken at approximately 1 yr of age. Carcass measurements including HCW, backfat over the 12th to 13th rib (BF), marbling score (MRB), and LM area (LMA) were collected for comparison with ultrasound data for predicting carcass composition. The 9th to 11th-rib section was removed and dissected into soft tissue and bone for determination of chemical composition, which was used to predict carcass fat and empty body fat (EBF). The predicted EBF averaged 23.7 +/- 4.0%. Multiple regression analysis indicated that carcass traits explained 72% of the variation in predicted EBF (EBF = 16.0583 + 5.6352 x BF + 0.01781 x HCW + 1.0486 x MRB - 0.1239 x LMA). Because carcass traits are not available on bulls intended for use as herd sires, another equation using predicted HCW (pHCW) and ultrasound measurements was developed (EBF = 39.9535 x uBF - 0.1384 x uLMA + 0.0867 x pHCW - 0.0897 x uBF x pHCW - 1.3690). This equation accounted for 62% of the variation in EBF. The use of an equation to predict EBF developed with steer composition data overpredicted the EBF predicted in these experiments (28.7 vs. 23.7%, respectively). In a validation study with 37 individually fed bulls, the use of the ultrasound-based equation in the CVDS to predict energy content of gain accounted for 60% of the variation in the observed efficiency of gain, with 1.5% bias, and identified 3 of the 4 most efficient bulls.

Adipose Tissue↗
PubMed2001

Factors associated with home versus institutional death among cancer patients in Connecticut.

OBJECTIVE: To assess the relationships between home death and a set of demographic, disease-related, and health-resource factors among individuals who died of cancer. DESIGN: Prospective cohort study. SETTING: All adult deaths from cancer in Connecticut during 1994. PARTICIPANTS: Six thousand eight hundred and thirteen individuals who met all of the following criteria: died of a cancer-related cause in 1994, had previously been diagnosed with cancer in Connecticut, and were age 18 and older at the time of death. MEASUREMENT: Site of death. RESULTS: Twenty-nine percent of the study sample died at home, 42% died in a hospital, 17% died in a nursing home, and 11% died in an inpatient hospice facility. Multivariate analysis indicated that demographic characteristics (being married, female, white, and residing in a higher income area), disease-related factors (type of cancer, longer survival postdiagnosis), and health-resource factors (greater availability of hospice providers, less availability of hospital beds) were associated with dying at home rather than in a hospital or inpatient hospice. CONCLUSIONS: The implications of this study for clinical practice and health planning are considerable. The findings identify groups (men, unmarried individuals, and those living in lower income areas) at higher risk for institutionalized death-groups that may be targeted for possible interventions to promote home death when home death is preferred by patients and their families. Further, the findings suggest that site of death is influenced by available health-system resources. Thus, if home death is to be supported, the relative availability of hospital beds and hospice providers may be an effective policy tool for promoting home death.

Aged↗
PubMed2001

Predicting individual feed requirements of cattle fed in groups.

A published model designed to predict individual feed required for the observed shrunk BW and ADG of growing cattle when fed in groups was modified and evaluated to improve its accuracy. This model is needed to accurately bill feed and compute cost of gain in marketing programs based on individual animal management. Because of its importance in predicting energy required for growth, a database of 401 steers was used to develop an equation to predict percentage of empty-body fat (EBF) from carcass measurements (12th rib fat thickness, hot carcass weight, USDA quality grade, and longissimus muscle area), which accounted for 61% of the variation in EBF with no bias (P > 0.1). When tested with an independent data set of 951 steers, the equation accounted for 51% of the variation with 1% proportional bias. The large variation in the carcass measurements at a particular EBF observed in this study indicates further improvement is limited by the inability of carcass measurements to account for variation in fat distribution in the various carcass components. Because of its importance in setting the target end point, a database of 1,355 steers and heifers was used to determine the relationship between EBF and USDA quality grade. These data indicate growing and finishing cattle reach Select and low-Choice quality grades at an EBF of 26.15 +/- 0.19 and 28.61 +/- 0.20%, respectively (P < 0.05). A data set of 228 steers from different breeds from two serial slaughter studies indicated 14.26 +/- 1.52 kg of empty BW change are required to increase EBF one percentage unit for cattle fed high-energy diets; this adjustment is needed to adjust final shrunk BW to the target EBF end point. The model to predict DM required with modifications developed in this study was evaluated with data from 365 individually fed cattle and it accounted for 74% of the variation in observed DM consumed with no bias (P > 0.1). When the revised model was applied to a commercial feedlot data set containing 12,105 steers and heifers, the total observed DM consumed was predicted with a bias of less than 1%. The model presented in this study accounts for differences known to affect animal requirements (breed type, BW and ADG, and weight at the target EBF end point) and can be used to fairly allocate feed to individuals fed in a group under commercial feedlot conditions.

Animal Feed↗
PubMed2000

Single-fiber myosin heavy-chain isoform composition of rodent laryngeal muscle: modulation by thyroid hormone.

BACKGROUND: Studies have shown that canine laryngeal muscle contains a large number of muscle fibers that coexpress varying combinations of myosin heavy-chain (MyHC) isoforms. Currently, it is not clear whether this phenomenon is unique to canine laryngeal muscle or occurs in all mammals. OBJECTIVES: To examine the single-fiber MyHC isoform composition of rodent laryngeal muscle and to examine the plasticity of single-fiber MyHC isoform composition via manipulation of thyroid state. RESULTS: (1) Findings of single-fiber electrophoretic analyses clearly demonstrate that most fibers in both the posterior cricoarytenoid and thyroarytenoid muscles exhibit MyHC polymorphism. However, the proportions and patterns of polymorphism appear to be muscle specific. (2) Although the fast type IIL isoform was observed in fibers from both muscles, it was always coexpressed in combination with other MyHC isoforms (ie, no pure type IIL fibers were found), and always represented a minor proportion of the total MyHC pool. (3) Altering the thyroid state proved a useful tool for exploring the scope of MyHC isoform expression in these muscles. While the posterior cricoarytenoid muscle seemed more sensitive to the thyroid state, transitions in both muscles were primarily confined to the fast type IIX and IIB MyHC isoforms. CONCLUSION: The findings of this study support the concept that single-fiber MyHC polymorphism occurs commonly in mammalian laryngeal muscle.

Animals↗
PubMed2000

Adult Chediak-Higashi parkinsonian syndrome with dystonia.

Chediak-Higashi syndrome (CHS) is a rare autosomal-recessive disorder characterized by immune deficiency, partial oculocutaneous albinism, and large eosinophilic, peroxidase-positive inclusion bodies in granule-containing cells. The adult form of CHS manifests during late childhood to early adulthood and is marked by various neurologic sequelae, including parkinsonism, dementia, spinocerebellar degeneration, and peripheral neuropathy. We report the case of a 29-year-old man with adult CHS who exhibited a progressive asymmetric parkinsonism, including rest tremor, and axial, cervical, and appendicular dystonia. The diagnosis was confirmed by the presence of characteristic large peroxidase-positive granules within leukocytes and markedly decreased natural killer cell function. Levodopa/carbidopa and amantadine provided benefit for tremor. CHS, although rare, should be considered in the differential diagnosis of young adult parkinsonism.

Adult↗
PubMed1998

A new concept in laryngeal muscle: multiple myosin isoform types in single muscle fibers of the lateral cricoarytenoid.

This report describes the first known investigation of canine laryngeal muscle in which single fibers were dissected and their myosin heavy chain (MHC) isoform content was analyzed. Both SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot techniques were used. The data from single fiber SDS-PAGE indicate that the lateral cricoarytenoid (LCA) is predominantly a fast muscle composed of the following MHC isoforms: Type I, 16.3%; Type IIA, 71.3%; Type IIX, 10.4%; and Type IIB, 2.0%. The results reveal a phenomenon that, to our knowledge, has not been previously described for laryngeal muscle: the presence of two or more MHC isoforms in a single canine LCA muscle fiber. A large number (41%) of muscle fibers coexpressed two or more MHC isoforms. The three most common patterns of coexpression were Type IIA/IIX (72%), Type IIA/I (16%), and Type IIA/IIX/I (8%). Interestingly, the fast Type IIX MHC isoform was typically present with other isoforms and rarely found by itself in individual fibers. Additional experiments are underway to determine whether other laryngeal muscles exhibit such an unusually high ratio of MHC isoform polymorphism.

Animals↗
PubMed1998

Novel transitions in MHC isoforms: separate and combined effects of thyroid hormone and mechanical unloading.

Single-fiber (n = 3,818 fibers) electrophoretic analyses were used to delineate the separate and combined effects of hyperthyroidism (T3) and hindlimb suspension (HS) on the myosin heavy chain (MHC) isoform composition (1-, 2-, and 4-wk time points) of the rat soleus muscle. The key findings of this study are as follows. First, T3 and HS both altered the distribution of MHC isoforms at the single-fiber level; however, the populations of fibers produced by these two interventions were clearly different from one another. Second, T3 + HS rapidly converted the soleus into a fast muscle, producing large increases in the relative contents of the fast type IIx and IIb MHC isoforms which were primarily expressed in several populations of hybrid fibers (e.g., types I/IIa/IIx, I/IIx/IIb, I/IIa/IIx/IIb). Finally, T3 + HS produced unique populations of hybrid fibers that did not adhere to the Ileft arrow over right arrow IIaleft arrow over right arrow IIxleft arrow over right arrow IIb sequential scheme of MHC plasticity. Collectively, the findings of this study demonstrate that the intervention of T3 + HS is a powerful model for manipulating and studying MHC isoform plasticity in slow skeletal muscle.

Animals↗
PubMed1997

Single-fiber and whole muscle analyses of MHC isoform plasticity: interaction between T3 and unloading.

Previous data suggest that separate interventions of hyperthyroidism (T3) and hindlimb suspension (HS) act on some but not all slow type I fibers in the soleus muscle. This may be due to the presence of "refractory" fibers that are unresponsive to either of these interventions. Alternatively, T3 and HS might act on different populations of slow type I fibers in the soleus muscle. Adult female Sprague-Dawley rats were assigned to 1) control, 2) T3, 3) HS, or 4) T3+HS. Nine animals were assigned to each group. Single-fiber electrophoretic analyses (n = 40 per muscle) of the soleus muscle demonstrated that the HS reduced the percentage of slow type I fibers from approximately 80% (control) to approximately 40% (HS) of the fiber population. Although hyperthyroidism affected a greater percentage of slow type I fibers than HS, a small population (approximately 10% of the slow type I fibers) were unaffected by T3. The combined intervention, in contrast, transformed all slow type I fibers into fibers expressing various combinations of fast myosin heavy chain (MHC) isoforms. These findings demonstrate that the soleus muscle does not contain so-called refractory fibers. They further suggest that the soleus muscle contains different populations of slow type I fibers that vary in their sensitivity to altered physiological conditions.

Animals↗
PubMed1997

Modulation of myosin isoform expression by mechanical loading: role of stimulation frequency.

This study tested for the hypothesis that mechanical loading, not stimulation frequency per se, plays a key role in determining the plasticity of myosin heavy chain (MHC) protein isoform expression in muscle undergoing resistance training. Female Sprague-Dawley rats were randomly assigned to resistance-training programs that employed active 1) shortening (n = 7) or 2) lengthening contractions (n = 8). The medial gastrocnemius (MG) muscles in each group trained under loading conditions that approximated 90-95% of maximum isometric tetanic tension but were stimulated at frequencies of 100 and approximately 25 Hz, respectively. Lengthening and shortening contractions were produced by using a Cambridge ergometer system. The MG muscles trained every other day, performing a total of 16 training session. Both training programs produced significant (P < 0.01) and similar reductions in the fast type IIB MHC protein isoform in the white MG muscle, reducing its relative content to approximately 50% of the total MHC protein isoform pool. These changes were accompanied by increases in the relative content of the fast type IIX MHC protein isoform that were of similar magnitude for both groups. The results of this study clearly demonstrate that stimulation frequency does not play a key role in modulating MHC isoform alterations that result from high-resistance training.

Animals↗
PubMed1996

Influence of mechanical loading on myosin heavy-chain protein and mRNA isoform expression.

The overall objective of the studies reported herein was to examine the effects of high-resistance training on myosin heavy-chain (MHC) protein and mRNA isoform expression. The findings from these studies can be summarized as follows: 1) there was a substantial increase in the fast type IIX MHC protein isoform content of the trained red and white medial gastrocnemius muscles, but this did not occur until after the eighth training session (i.e., 16 days); 2) single-fiber analyses demonstrated that many so-called fast type IIB fibers contained small amounts of the fast type IIX MHC protein isoform and that the high-resistance training program altered the bias of fast type IIB-type IIX MHC protein isoform distribution in these fibers but did not increase the number of fibers that could be categorized as exclusively fast type IIX fibers; 3) the high-resistance training program produced a rapid (i.e., after two training sessions) elevation in the fast type IIX MHC mRNA isoform and a corresponding repression of the fast type IIB MHC mRNA isoform; and 4) the dose-response study revealed that as few as 10 contractions (40 s) per training session were capable of elevating the expression of the fast type IIX MHC mRNA isoform by approximately 250%. These collective findings demonstrate that high-resistance training is a powerful modulator of MHC protein isoforms and that pretranslational mechanisms are very sensitive to even small amounts of high-resistance training.

Animals↗
PubMed1996

Microgravity-induced transformations of myosin isoforms and contractile properties of skeletal muscle.

This study examined the effects of microgravity (14 days) on 1) the contractile properties of the soleus (Sol), an antigravity skeletal muscle; and 2) the myosin heavy chain (MHC) protein and mRNA isoform content of the Sol, vastus intermedius (VI), plantaris (Plan), and tibialis anterior (TA) muscles. The force-velocity relationships of the flight Sol muscles had a significant reduction in maximal isometric tension (-37%) and a corresponding increase in maximal shortening velocity (+20%). Additionally, the force-frequency relationship of the flight Sol muscles was shifted to the right of the ground-based control group. Microgravity had the greatest effect on muscle fiber composition in the Sol muscle, with a reduction in slow muscle fibers and a corresponding increase in muscle fibers categorized as hybrid fibers. The estimated absolute MHC isoform content was altered to the greatest extent in the Sol and VI muscles, with significant decreases and elevations in the slow type I and fast type IIX MHC protein isoforms, respectively. Consistent with the protein data, both the flight Sol and VI muscles exhibited significant elevations in the fast type IIX MHC mRNA isoform. In contrast, however, the flight Plan and TA groups had significant increases in the fast type IIB MHC mRNA isoform content without corresponding changes at the protein level. The results of this study suggest that spaceflight of even short duration produces important changes in the contractile properties of antigravity skeletal muscle. These changes are mediated by alterations in MHC phenotype and reductions in muscle mass. In some instances, the alterations in MHC mRNA isoform content seemed to be uncoupled from those occurring at the protein level. This apparent uncoupling between mRNA and protein expression demonstrates that the effects of microgravity must be better understood at the transcriptional, translational, and post-translational levels.

Animals↗
PubMed1995

Recent trends in the use of inhaled beta 2-adrenergic agonists and inhaled corticosteroids in Saskatchewan.

OBJECTIVE: To examine recent trends in the use of inhaled beta 2-adrenergic agonists and inhaled corticosteroids for the treatment of asthma among Saskatchewan residents and to determine whether these trends are in keeping with widely publicized guidelines recommending a reduction in the use of agents to treat symptoms (i.e., inhaled beta 2-adrenergic agonists) and increased use of prophylactic agents (i.e., inhaled corticosteroids). DESIGN: Descriptive pharmacoepidemiologic study conducted with the use of data from the computerized database of the Saskatchewan Prescription Drug Plan. SETTING: Saskatchewan. PATIENTS: Saskatchewan residents 5 to 54 years of age who received one or more outpatient prescriptions for drugs to treat asthma (inhaled drugs, ingested beta 2-adrenergic agonists and ingested methylxanthines) from 1989 to 1993. OUTCOME MEASURES: Epidemiologic trends, calculated for each year: number of prescriptions per 1,000 persons; number of patients who received prescriptions for inhaled corticosteroids, inhaled beta 2-adrenergic agonists and any type of drug to treat asthma; mean number of such prescriptions per patient; and weighted mean amount of salbutamol, fenoterol and beclomethasone dispensed per patient. RESULTS: There has been an increase in the proportion of the population receiving prescriptions for drugs to treat asthma. The number of patients receiving these drugs per 1,000 people rose during the study period from 33.38 to 46.59 for any drug to treat asthma, from 24.70 to 33.77 for inhaled beta 2-adrenergic agonists and from 6.1 to 19.9 for inhaled corticosteroids. The mean number of prescriptions per patient decreased steadily for all drugs to treat asthma (from 5.34 in 1989 to 3.88 in 1993), for inhaled beta 2-adrenergic agonists (from 4.35 to 3.09) and for inhaled corticosteroids (from 2.98 to 2.25). The weighted mean amount of inhaled salbutamol dispensed per patient per year decreased by 40%, from 178.08 mg in 1989 to 109.14 mg in 1993. The weighted amount of fenoterol dispensed per patient per year declined even more, by 58%, from 387.91 mg in 1989 to 164.00 mg in 1993. Conversely, the weighted amount of inhaled beclomethasone dispensed per patient per year increased by 35% from 46.95 mg in 1989 to 63.50 mg in 1992, then dropped to 56.17 mg per year in 1993. CONCLUSION: These data demonstrate a substantial change in Saskatchewan in the prescribing of drugs to treat asthma; they suggest that many physicians responded to current guidelines advocating increased attention to prevention of airway inflammation in the treatment of asthma.

Administration, Inhalation↗
PubMed1995

Functional and cellular adaptations of rodent skeletal muscle to weightlessness.

Microgravity perturbs a wide variety of physiological systems. Specifically, skeletal muscle has been shown to undergo dramatic changes even during spaceflights of short durations. Despite a growing body of knowledge, many critical issues related to sarcomeric gene expression and the translation of this information into muscle function remain relatively unexplored. Ultimately, the types and quantities of contractile proteins present in skeletal muscle fibers determine muscle function. As shown in Figure 1, the pool of contractile proteins is determined by 4 important processes: i) transcription of sarcomeric genes; ii) translation of sarcomeric mRNA transcripts; iii) myofibrillar assembly; and iv) myofibrillar disassembly (i.e., protein degradation). Any factor(s) affecting one or more of these systems will ultimately impact skeletal muscle function. With respect to Figure 1, the objective of this paper is to provide a focused summary of the affects of short duration spaceflights on myosin composition of the soleus (SOL) muscle. This will be achieved by describing the affects of spaceflight upon: i) mechanical properties of skeletal muscle that are determined by the types and quantity of myosin; ii) myosin heavy chain (MHC) protein isoform composition; and ii) MHC mRNA isoform content. Data reported in this paper are from spaceflight missions having durations of 6 (PARE-02;2) and 14 days (SLS-2).

Animals↗
PubMed1994

Effect of spaceflight on skeletal muscle: mechanical properties and myosin isoform content of a slow muscle.

This study examined changes in contractile, biochemical, and histochemical properties of slow antigravity skeletal muscle after a 6-day spaceflight mission. Twelve male Sprague-Dawley rats were randomly divided into two groups: flight and ground-based control. Approximately 3 h after the landing, in situ contractile measurements were made on the soleus muscles of the flight animals. The control animals were studied 24 h later. The contractile measurements included force-velocity relationship, force-frequency relationship, and fatigability. Biochemical measurements focused on the myosin heavy chain (MHC) and myosin light chain profiles. Adenosine-triphosphatase histochemistry was performed to identify cross-sectional area of slow and fast muscle fibers and to determine the percent fiber type distribution. The force-velocity relationships of the flight muscles were altered such that maximal isometric tension (Po) was decreased by 24% and maximal shortening velocity was increased by 14% (P < 0.05). The force-frequency relationship of the flight muscles was shifted to the right of the control muscles. At the end of the 2-min fatigue test, the flight muscles generated only 34% of Po, whereas the control muscles generated 64% of Po. The flight muscles exhibited de novo expression of the type IIx MHC isoform as well as a slight decrease in the slow type I and fast type IIa MHC isoforms. Histochemical analyses of flight muscles demonstrated a small increase in the percentage of fast type II fibers and a greater atrophy of the slow type I fibers. The results demonstrate that contractile properties of slow antigravity skeletal muscle are sensitive to the microgravity environment and that changes begin to occur within the 1st wk. These changes were at least, in part, associated with changes in the amount and type of contractile protein expressed.

Adenosine Triphosphatases↗
PubMed1994

The effects of space flight on the contractile apparatus of antigravity muscles: implications for aging and deconditioning.

Previous studies have shown that the unloading of skeletal muscle, as occurring during exposure to space flight, exerts a profound effect on both the mass (cross sectional area) of skeletal muscle fibers and the relative expression of protein isoforms comprising the contractile system. Available information suggests that slow (type I) fibers, comprising chiefly the antigravity muscles of experimental animals, in addition to atrophying, undergo alterations in the type of myosin heavy chain (MHC) expressed such that faster isoforms become concomitantly expressed in a sub-population of slow fibers when insufficient force-bearing activity is maintained on the muscle. Consequently, these transformations in both mass and myosin heavy chain phenotype could exert a significant impact on the functional properties of skeletal muscle as manifest in the strength, contractile speed, and endurance scope of the muscle. To further explore these issues, a study was performed in which young adult male rats were exposed to zero gravity for six days, following which, the antigravity soleus muscle was examined for a) contractile properties, determined in situ and b) isomyosin expression, as studied using biochemical, molecular biology, and histochemical/immunohistochemical techniques.

Aging↗
PubMed1992

A population-wide profile of prescription drug use in Saskatchewan, 1989.

OBJECTIVE: To measure the prevalence of prescription drug use in Saskatchewan in 1989. DESIGN: Retrospective study. PARTICIPANTS: A total of 961,203 Saskatchewan residents (including those who died or were born during the study year) who were eligible for coverage under the Saskatchewan Prescription Drug Plan. The study population represented 94% of the province's total population; those excluded were mostly status Indians (for whom a federal plan is available). MAIN RESULTS: At least one prescription was received by 66.0% of the study population in 1989. The mean number of prescriptions per patient was 8.2, and the mean cost of drug material per prescription was $13.95. Females received substantially more prescriptions than males; the difference was particularly notable for cardiovascular agents, antidepressants and benzodiazepines. In the senior population 80.8% received at least one prescription; the mean number of prescriptions per patient was 18.4. The most commonly dispensed drug for the entire study population was amoxicillin (290 prescriptions per 1000 people); triazolam was the most frequently dispensed central nervous system drug (74 prescriptions per 1000 people). Regional variation in overall drug use was remarkably small, although it increased at the drug-class level, especially for tranquillizers. The use of cardiovascular drugs was 27% to 32% higher (depending on how use was measured) per Regina resident than per Saskatoon resident. Benzodiazepines were commonly used on a long-term basis, despite recommendations to the contrary. CONCLUSIONS: The results quantify the prevalence of prescription drug use, underscore the importance of careful management of drug therapy by physicians and pharmacists (especially for seniors), illustrate substantial variation in drug therapy strategies and raise questions about utilization of benzodiazepines and cardiovascular drugs.

Age Factors↗