Serious infections in patients with myasthenia gravis: population-based cohort study.

BACKGROUND AND PURPOSE: To characterize the frequency and risk of serious infections in patients with myasthenia gravis (MG) relative to age/sex/area-matched comparators. METHODS: This was a population-based cohort study in Ontario, Canada of patients with newly-diagnosed MG and 1:4 age/sex/area-matched general population comparators accrued from 1 April 2002 to 31 December 2015. The main outcome was a serious infection, defined by a primary diagnosis code on a hospitalization or emergency department record. We computed crude overall and sex-specific rates of infection among patients with MG and comparators, and the frequency of specific types of infection. Adjusted hazard ratios and 95% confidence intervals were estimated using Cox regression. RESULTS: Among 3823 patients with MG, 1275 (33.4%) experienced a serious infection compared with 2973/15 292 (19.4%) of comparators over a mean follow-up of over 5 years. Crude infection rates among patients with MG were twice those in comparators (72.5 vs. 35.0 per 1000 person-years, respectively). The most common infection types were respiratory infections, particularly bacterial pneumonia. After adjustment for potential confounders, MG was associated with a 39% increased infection risk (adjusted hazard ratio, 1.39; 95% confidence intervals, 1.28-1.51). CONCLUSIONS: Patients with MG are at a significantly higher absolute and relative risk of serious infections compared with age/sex/area-matched comparators. This needs to be considered when selecting MG treatments and when planning vaccination/prophylaxis. Determining whether this risk is due to the use of immunosuppressive medications (vs. MG itself) is an important area for future research.

Progression through diabetes therapies among new elderly users of metformin: a population-based study.

AIMS: To examine temporal changes in progression to second-line therapies among older patients with diabetes newly treated with metformin. METHODS: We conducted a population-based study among residents of Ontario, Canada aged 66 years and older with diabetes newly treated with metformin monotherapy in 1997, 2000, 2003 or 2006. Each annual cohort was followed until progression to a second oral hypoglycaemic agent, insulin or until 31 December 2010. Time to progression to a second oral hypoglycaemic agent or insulin was compared across the cohorts. RESULTS: In the four annual cohorts, we identified a total of 46 104 people newly treated with metformin monotherapy. The median time to progression to any second diabetes therapy lengthened significantly over time, from 5.0 years in 1997 to 6.1 years in 2003 (P < 0.0001). Similarly, the time to progression to insulin lengthened over the study period (P = 0.03). Furthermore, the choice of second-line therapy changed over time. While 80.7% of new metformin users in 1997 progressed to glyburide therapy as second-line treatment, the corresponding figure by 2006 was only 45.1% as newer treatment options emerged. CONCLUSIONS: Although recent guidelines recommend aggressive intensification of oral therapy for patients with Type 2 diabetes, older Ontarians with diabetes who started metformin in 2006 remained on monotherapy for longer than those who started in 1997. Furthermore, although there is no consensus regarding a preferred second-line therapy, the introduction of new alternatives has led to greater variation in the selection of second-line therapies in this population.

Trends in selection and timing of first-line pharmacotherapy in older patients with type 2 diabetes diagnosed between 1994 and 2006.

AIMS: To characterize temporal trends in the selection and timing of first-line pharmacotherapy among older patients with Type 2 diabetes. DESIGN AND METHODS: We studied five population-based cohorts every 3 years, from 1994 to 2006. In each of those years, we identified all subjects aged 66 years or older newly diagnosed with diabetes and determined the initial glucose-lowering drug and the time between diagnosis and drug initiation. We calculated the proportion of patients prescribed each agent and estimated time from diagnosis to initiation using Kaplan-Meier survival analysis. RESULTS: We identified a total of 64 368 eligible people who initiated drug therapy during the study period. From 1994 to 2006, first-line metformin use increased from 20.1 to 79.0%. Glyburide (glibenclamide) decreased from 71.1% of all first-line therapies in 1994 to 9.8% in 2006, while first-line use of insulin or combination therapy have changed little at approximately 5% each. No other medication exceeded 2% of first-line therapies. The median time from diagnosis to initiation of pharmacotherapy increased dramatically during the study period, from 1.8 years in 1994 to 4.6 years in 2006. CONCLUSIONS: Metformin has become the most commonly used initial medication for the treatment of diabetes. Although guidelines have evolved to recommend more aggressive initiation and intensification of pharmacotherapy, our results suggest that the time from diagnosis to initiation has increased substantially.

Osteoporosis medication prescribing in British Columbia and Ontario: impact of public drug coverage.

UNLABELLED: We compared the patterns of osteoporosis medication prescribing between two provinces in Canada with different public drug coverage policies. Oral bisphosphonates were the primary drugs used, yet access to the second-generation oral bisphosphonates (alendronate, risedronate) was limited in one region. Implications of differential access to oral bisphosphonates warrants further study. INTRODUCTION: Approved therapies for treating osteoporosis in Canada include bisphosphonates, calcitonin, denosumab, raloxifene, and teriparatide. However, significant variation in access to these medications through public drug coverage exists across Canada. We sought to compare patterns of osteoporosis medication prescribing between British Columbia (BC) and Ontario. METHODS: Using dispensing data from BC (PharmaNet) and Ontario (Ontario Drug Benefits), we identified all new users of osteoporosis medications aged 66 or more years from 1995/1996 to 2008/2009. We summarized the number of new users by fiscal year, sex, and index drug for each province. BC data were also stratified by whether drugs were dispensed within or outside public PharmaCare. RESULTS: We identified 578,254 (n = 122,653 BC) eligible new users. Overall patterns were similar between provinces: (1) most patients received an oral bisphosphonate (93% in BC and 99% in Ontario); (2) etidronate prescribing declined after 2001/2002, reaching a low of 41% in BC and 10% in Ontario in 2008/2009; and (3) the proportion of males treated increased over time, from 7% in 1996/1997 to 25% in 2008/2009. However, we note major differences within versus outside the BC PharmaCare system. In particular, <2% of drugs dispensed within PharmaCare compared to 79% of drugs dispensed outside PharmaCare were for a second-generation bisphosphonate (alendronate or risedronate). CONCLUSIONS: Oral bisphosphonates are the primary drugs used to treat osteoporosis in Canada. Prescribing practices changed over time as newer medications came to market, yet access to second-generation bisphosphonates through BC PharmaCare was limited. Implications of differential access to oral bisphosphonates warrants further study.

Bisphosphonate prescribing, persistence and cumulative exposure in Ontario, Canada.

UNLABELLED: We studied new users of oral bisphosphonates and found that less than half persisted with therapy for 2 years, and interruptions in use were common. During a median observation period of 4.7 years, 10% of patients filled only a single prescription, 37% switched therapies and median cumulative exposure was 2.2 years. INTRODUCTION: We sought to describe bisphosphonate prescribing, persistence and cumulative exposure among seniors in Ontario, Canada. METHODS: We used Ontario Drug Benefit pharmacy claims to identify residents aged ≥ 66 years who initiated oral bisphosphonate therapy between April 1996 and March 2009. The first date of bisphosphonate dispensing was considered the index date. Persistence with therapy was defined as continuous treatment with no interruption exceeding 60 days. We examined persistence with therapy and the number of extended gaps (>60 days) between prescriptions over time periods ranging from 1 to 9 years. We also identified the proportion of patients filling only a single prescription and switching to a different bisphosphonate, and calculated the median days of exposure irrespective of gaps in therapy. RESULTS: A total of 451,113 eligible new bisphosphonate users were identified: mean age = 75.6 years (SD = 6.9), 84% female, and median follow-up length = 4.7 years. Persistence with therapy declined from 63% at 1 year to 46% at 2 years and 12% at 9 years. Among those with at least 5 years of follow-up (n = 213,029), 61% had one or more extended gaps in bisphosphonate therapy. Overall, 10% of patients filled only a single prescription, 37% switched to a different bisphosphonate and the median exposure was 2.2 years. CONCLUSION: Less than half of patients persisted with bisphosphonate therapy for 2 years and interruptions in therapy were common, with most patients experiencing two or more >60-day gaps in therapy. Interventions are needed to improve persistence with bisphosphonate therapy and reduce the frequency of gaps in treatment.

Osteoporosis quality indicators using healthcare utilization data.

SUMMARY: Healthcare utilization data may be used to examine the quality of osteoporosis management by identifying dual-energy X-ray absorptiometry (DXA) testing (sensitivity = 98%, specificity = 93%) and osteoporosis pharmacotherapy (κ = 0.81) with minimal measurement error. INTRODUCTION: In osteoporosis, key quality indicators among older women include risk assessment by DXA and/or pharmacotherapy within 6 months following fracture. METHODS: The purpose of this study was to examine healthcare utilization data for use as quality indicators of osteoporosis management. We linked data from 858 community-dwelling women aged over 65 years who completed a standardized telephone interview about osteoporosis management to their healthcare utilization (medical and pharmacy claims) data. Agreement between self-report of osteoporosis pharmacotherapy and pharmacy claims was examined using kappa statistics. We examined the sensitivity and specificity of medical claims to identify DXA testing as well as the sensitivity and specificity of medical and pharmacy claims to identify those with DXA-documented osteoporosis (T-score ≤ -2.5). RESULTS: Participants were aged 75 (SD = 6) years on average; 96% were Caucasian. Agreement between self-report and claims-based osteoporosis pharmacotherapy was very good (κ = 0.81; 95% CI = 0.76, 0.86). The sensitivity of medical claims to identify DXA testing was 98% (95% CI = 95.9, 99.1), with estimated specificity of 93% (95% CI = 89.8, 95.4). We abstracted DXA results from test reports of 359 women, of whom 114 (32%) were identified with osteoporosis. Medical (osteoporosis diagnosis) and pharmacy (osteoporosis pharmacotherapy) claims within a year after DXA testing had a sensitivity of 80% (95% CI = 71.3, 86.8) and specificity of 72% (95% CI = 66.2, 77.8) to identify DXA-documented osteoporosis. CONCLUSION: Healthcare utilization data may be used to examine the quality of osteoporosis management by identifying DXA testing and osteoporosis pharmacotherapy (care processes) with minimal measurement error. However, medical and pharmacy claims alone do not provide a good means for identifying women with underlying osteoporosis.

Supracondylar humeral fractures in children: ten years' experience in a teaching hospital.

Although supracondylar fracture is a very common elbow injury in childhood, there is no consensus on the timing of surgery, approach for open reduction and positioning of fixation wires. We report our ten-year experience between 1993 and 2003 in 291 children. Most fractures (285; 98%) were extension injuries, mainly Gartland types II (73; 25%) and III (163; 56%). Six (2%) were open fractures and a neurovascular deficit was seen in 12 (4%) patients. Of the 236 children (81%) who required an operation, 181 (77%) were taken to theatre on the day of admission. Most (177; 75%) of the operations were performed by specialist registrars. Fixation was by crossed Kirschner wires in 158 of 186 (85%) patients and open reduction was necessary in 52 (22%). A post-operative neurological deficit was seen in nine patients (4%) and three (1%) required exploration of the ulnar nerve. Only 22 (4%) patients had a long-term deformity, nine (3%) from malreduction and three (1%) because of growth arrest, but corrective surgery for functional limitation was required in only three (1%) patients.

Repression of preprotachykinin-A promoter activity is mediated by a proximal promoter element.

The rat preprotachykinin-A promoter, which is able to direct reporter gene expression in adult dorsal root ganglia neurons grown in culture, has no detectable activity in HeLa and PC12 cells. DNAase 1 footprinting and electrophoretic mobility shift analyses with HeLa nuclear extract indicated the presence of a protein complex binding to a region of the rat preprotachykinn-A gene promoter between the TATA box and the major transcriptional start site. We demonstrate that the sequence of the preprotachykinin-A promoter spanning nucleotides -47 to +92 functions to repress reporter gene expression in HeLa and PC12 cells but not in adult rat dorsal root ganglia grown in culture, and that this repression is correlated with a protein(s) binding to the element between the TATA box and major transcription initiation site. These results indicate that the tissue-specific expression of the preprotachykinin-A gene could require the interaction of both positive and negative regulatory DNA elements.

Three immediate early gene response elements in the proximal preprotachykinin-A promoter in two functionally distinct domains.

The preprotachykinin-A promoter contains two blocks of DNA sequence, with a high degree of homology to one another, both containing activator protein 1/cAMP response element-like elements which constitute cis-acting regulatory domains. These two domains are differentially regulated in HeLa cells and primary cultures of dorsal root ganglion neurons when they are placed in the context of a reporter gene driven by the c-fos minimum promoter. One of the domains, corresponding to a region of the preprotachykinin promoter spanning nucleotides -345 to -308, contains two activator protein 1 elements adjacent to an E-box binding protein consensus sequence. Both of the activator protein 1 elements can bind a complex containing c-fos/c-fos related antigen proteins and the adjacent E-box element is specifically recognized by proteins present in HeLa nuclear extract. This domain requires the synergistic action of both activator protein 1 elements to drive expression of the reporter gene in both HeLa and dorsal root ganglion cells. The second or proximal domain spans nucleotides -198 to -155 and contains a previously characterized activator protein 1/cAMP response element/ATF enhancer element which, in contrast to the activator protein 1 elements in the distal domain, functions in both HeLa and dorsal root ganglion cells as one copy. This domain is differentially regulated in HeLa and dorsal root ganglia. The previously characterized enhancer activity is repressed in the context of the extended cis-acting domain in HeLa cells but remains active in dorsal root ganglion, although no further enhancement of activity supported by the single enhancer is observed when in the context of the extended sequence. This proximal domain, in addition to binding the enhancer complex, can be bound by at least two other complexes, one of which binds to an E-box consensus sequence. As the elements corresponding to the E-box consensus in both domains cross-compete for binding of specific complex(es) it would appear that repression of the activity of the proximal domain is correlated with a specific protein complex binding adjacent to the characterized enhancer in the region spanning nucleotides -198 to -155. The preprotachykinin-A proximal promoter is therefore bound by multiple activator protein I complexes, which in the context of the cis-acting domains in which they are present can be differentially regulated. In the proximal domain their function may also be regulated in a tissue-specific manner by other proteins which bind to adjacent regulatory elements.

Altered surface and cyst epithelium of ovaries removed prophylactically from women with a family history of ovarian cancer.

Despite intensive investigation, the nature of epithelial ovarian cancer precursors remains controversial. Because women with a strong family history of ovarian cancer have a high probability of developing ovarian cancer themselves, ovaries removed prophylactically from such patients provide an opportunity to identify early neoplastic changes. Ovaries removed from 64 consecutive patients undergoing prophylactic oophorectomy and from 30 women with normal ovaries and no known family history of ovarian cancer were examined by light microscopy for a number of histopathologic features and by image cytometry for abnormalities of the cyst and surface epithelium. All analyses were performed without knowledge of the family history. Seven benign, but no tumors of low malignant potential or malignant epithelial tumors were found in the prophylactic oophorectomy group. There were more cortical inclusion cysts in the prophylactically removed than controls ovaries (P = .016), but no other architectural features differed between the two groups. No abnormalities were found in the surface or cyst epithelium in either group by light microscopy. In contrast, image analysis identified differences in the nuclei between the two groups, indicating that those from the surface epithelium of prophylactically removed ovaries were larger and contained more heterogeneously dense chromatin than those of controls, and that nuclei of the cyst epithelium had more irregular outlines. Ovarian epithelium from prophylactically removed ovaries exhibit abnormalities that are only identified by image analysis, and which might represent early preneoplastic changes. Such ovaries may be useful for identifying early molecular changes in ovarian cancer.

Characterisation of a functional E box motif in the proximal rat preprotachykinin-A promoter.

Three E box motifs, which are upstream of the major transcriptional start site, have previously been characterised in the rat preprotachykinin-A (rPPT) promoter. Only one of these, in the proximal promoter spanning nucleotides -67 to -47, has been demonstrated to support reporter gene expression in clonal cell lines under basal growth conditions. Here we demonstrate that the reporter gene expression can be further induced by the action of phorbol 12-myristate 13-acetate (TPA) and nerve growth factor (NGF), respectively, in both HeLa and the neuronally derived PC12 cells. This response is due to the E box motif and not an overlapping consensus sequence for a putative AP1 element, a class of element previously demonstrated to respond to both TPA and NGF in these cell lines. Finally, we demonstrate that this E box motif can support similar levels of reporter gene expression in primary cultures of dorsal root ganglion neurons as observed in clonal cell lines, demonstrating that E box binding complexes can (1) function as a transcriptional regulator in dorsal root ganglion neurons and (2) bind to and therefore presumably regulate rPPT promoter activity.

Redisplacement after manipulation of distal radial fractures in children.

We reviewed 68 fractures of the distal radius in children, all treated by primary manipulation and plaster immobilisation. Complete displacement of the fracture and failure to achieve a perfect reduction were both associated with a significant increase in the chance of redisplacement. We recommend the use of percutaneous Kirschner wires to maintain a satisfactory position in all cases in which a perfect reduction cannot be achieved.

The Roper-Day total shoulder replacement.

A simple unconstrained shoulder prosthesis has been used in 22 patients (25 shoulders) with incapacitating pain and severely damaged joints who, because of age or generalised rheumatoid disease, have limited functional requirements. All reported good and lasting pain relief. Improvement in range of movement was modest, but there was marked improvement in function. In this group of patients, rotator cuff damage is common, but does not preclude a satisfactory result.

Femoral osteotomy in Perthes' disease. Results at maturity.

Upper femoral osteotomy is a recognised treatment for selected patients with Perthes' disease. The results of this procedure were investigated at skeletal maturity in 44 patients (48 hips). The indication for operation was Catterall group II, III, and IV hips with 'head-at-risk' signs. Harris and Iowa scores were calculated clinically, and each hip was assigned radiographically to one of the five Stulberg classes, its initial Catterall grading checked and other relevant indices measured. Results showed excellent clinical function. Shortening was present in 14 hips (29%) and a positive Trendelenburg's sign was seen in 12 (25%). On radiographic assessment 58% of hips were Stulberg class I or II, with a good prognosis. The results of femoral osteotomy were better than those for conservatively treated hips in all age groups except those under five years.

Olecranon spur.

Full extension of the elbow is normally made possible by accommodation of the olecranon within an appropriately shaped fossa in the distal humerus. We report three cases where disability has resulted from an abnormally shaped olecranon.

Hypertrophic osteitis of the medial end of the clavicle.

A 9-year-old boy had a spontaneous onset of enlargement of the medial end of the clavicle due to extensive sclerosis and periosteal reaction. There was no clinical or laboratory evidence of infection. Biopsy revealed an inflammatory exudate, and histochemical staining for Langerhans'-cell histiocytosis was negative. Hypertrophic sclerosis causing painful enlargement of the medial end of the clavicle in isolation should be distinguished from condensing osteitis and chronic recurrent multifocal osteomyelitis. An early biopsy to exclude neoplasia is recommended.

Proximal femoral resection without post-operative traction for the painful dislocated hip in young patients with cerebral palsy: a review of 79 cases.

Proximal femoral resection (PFR) is a proven pain-relieving procedure for the management of patients with severe cerebral palsy and a painful displaced hip. Previous authors have recommended post-operative traction or immobilisation to prevent a recurrence of pain due to proximal migration of the femoral stump. We present a series of 79 PFRs in 63 patients, age 14.7 years (10 to 26; 35 male, 28 female), none of whom had post-operative traction or immobilisation. A total of 71 hips (89.6%) were reported to be pain free or to have mild pain following surgery. Four children underwent further resection for persistent pain; of these, three had successful resolution of pain and one had no benefit. A total of 16 hips (20.2%) showed radiographic evidence of heterotopic ossification, all of which had formed within one year of surgery. Four patients had a wound infection, one of which needed debridement; all recovered fully. A total of 59 patients (94%) reported improvements in seating and hygiene. The results are as good as or better than the historical results of using traction or immobilisation. We recommend that following PFR, children can be managed without traction or immobilisation, and can be discharged earlier and with fewer complications. However, care should be taken with severely dystonic patients, in whom more extensive femoral resection should be considered in combination with management of the increased tone.

A population-based assessment of the drug interaction between levothyroxine and warfarin.

Most drug interaction resources suggest that levothyroxine can dramatically potentiate the effect of warfarin. However, the mechanistic basis of the interaction is speculative, and little evidence supports a meaningful drug interaction. We conducted a population-based nested case-control study to examine the risk of hospitalization for hemorrhage following the initiation of levothyroxine in a cohort of 260,076 older patients receiving warfarin. In this group, we identified 10,532 case subjects hospitalized for hemorrhage and 40,595 controls. In the primary analysis, we found no association between hospitalization for hemorrhage during warfarin therapy and initiation of levothyroxine in the preceding 30 days (adjusted odds ratio 1.11, 95% confidence interval 0.67-1.86). Secondary analyses using more remote initiation of levothyroxine also found no association. These findings suggest that concerns about a clinically meaningful levothyroxine-warfarin drug interaction are not justified. Drug interaction resources that presently characterize this interaction as important should reevaluate this classification.

Elastic intramedullary nailing of paediatric fractures of the forearm: a decade of experience in a teaching hospital in the United Kingdom.

We present the results of 90 consecutive children with displaced fractures of the forearm treated by elastic stable intramedullary nailing with a mean follow-up of 6.6 months (2.0 to 17.6). Eight (9%) had open fractures and 77 (86%) had sustained a fracture of both bones. The operations were performed by orthopaedic trainees in 78 patients (86%). All fractures healed at a mean of 2.9 months (1.1 to 8.7). There was one case of delayed union of an ulnar fracture. An excellent or good functional outcome was achieved in 76 patients (84%). There was no statistical difference detected when the grade of operating surgeon, age of the patient and the diaphyseal level of the fracture were correlated with the outcome. A limited open reduction was required in 40 fractures (44%). Complications included seven cases of problematic wounds, two transient palsies of the superficial radial nerve and one case each of malunion and a post-operative compartment syndrome. At final follow-up, all children were pain-free and without limitation of sport and play activities. Our findings indicate that the functional outcome following paediatric fractures of the forearm treated by elastic stable intramedullary nailing is good, without the need for anatomical restoration of the radial bow.