Serum sodium as a risk factor for in-hospital mortality in acute unselected general medical patients

BACKGROUND

Serum sodium has been shown to predict mortality in heart and liver failure.

AIM

To determine whether serum sodium independently predicts in-hospital mortality during any emergency medical admission.

DESIGN

An analysis was performed of all emergency medical patients admitted to St James's Hospital (SJH), Dublin between 1 January 2002 and 31 December 2006, using the hospital inpatient enquiry (HIPE) system, linked to the patient administration system and laboratory datasets. Hospital mortality was obtained from a database of 20 deaths occurring during the same period under physicians participating in the 'on call' roster.

METHODS

The serum sodium was determined at admission in all cases where it was deemed clinically necessary. Logistic regression was used to calculate crude and 25 adjusted odds ratios (ORs). Factors adjusted for included age, illness severity score (Modified Apache II score), major disease category, ICU stay, year effect, blood transfusion, gender and sepsis.

RESULTS

A total of 14 239 patients (47.5% male) were included in the analysis. Mortality had a U-shaped distribution and was highest in patients whose sodium level was <125 or >140 mmol/l. The unadjusted OR of death within 30 days of admission was 3.36 (95% CI 2.59-4.36) and 4.07 (95% CI 2.95-5.63) with sodium level <125 and >140 mmol/l, respectively. Adjustment for all of the factors above reduced the mortality odds in all hyponatraemia groups but all remained significant predictors of mortality. After adjustment for illness severity score the OR ratio for death in the >140 mmol/l group fell to 1.41 (95% CI 0.97-2.07).

DISCUSSION

The serum sodium is a powerful initial marker of likely mortality in unselected general medical patients. The increased death rate in hyponatraemic patients is independent of other clinical variables, whereas mortality in the hypernatraemic group is primarily a factor of illness severity.

An analysis of the utilisation and expenditure of medicines dispensed for the management of severe asthma

There are approximately 6,300 people in Ireland with a diagnosis of Chronic Obstructive Pulmonary Disease (COPD) and with a fast growing elderly population the incidence of COPD is likely to increase. This study examines the prescribing patterns of medicines dispensed for the management Asthma/COPD in patients over the age of 35 years using the HSE-Primary Care Reimbursement Services (PCRS) prescribing databases. The HSE-PCRS pharmacy claims data, which covers all those over 70 years of age and means tested for those less than 70 years, was analysed for the years 2005/2006. Approximately 26,548 (17.9%) of patients who were prescribed a respiratory drug received inhaled short-acting beta2 agonists in combination with a regular standard-dose inhaled corticosteroid. A further 5,044 (3.4%) were also prescribed a regular inhaled long-acting beta2 agonist (salmeterol or formoterol). A total of 2506 patients (6.2%) on combination therapy were co-prescribed four different anti-asthmatic treatments inclusive of oral prednisolone. A small proportion of the patients prescribed a respiratory drug were co-prescribed nicotine replacement therapy (n = 5177, 3.5%). In total there were 9,728 (6.2%) patients prescribed a mucolytic drug in combination with a respiratory drug and the rate of co-prescribing with antibiotics was 22%. COPD is a debilitating disease that is primarily caused by smoking and is therefore largely preventable. The HSE-PCRS pharmacy claims data is a valuable tool for helping to assess the burden of this disease in the Irish context.

Significant psychological morbidity occurs in irritable bowel syndrome: a case-control study using a pharmacy reimbursement database

BACKGROUND

Psychological problems are associated with IBS but the strength of this association is unclear.

AIM

To assess co-prescribing of antispasmodic and CNS-acting drugs through a nested case-control study.

METHODS

A national dispensing database identified patients who were first dispensed antispasmodic medicines for a continuous 3-month period or more during 2006, using 2005 as a run-in period. Each patient was matched with four control patients and excluded if they received drugs indicated for IBD.

RESULTS

Four hundred and seven patients commenced antispasmodic drugs during 2006. These patients were matched with 1628 controls. In 2005, patients subsequently prescribed antispasmodics were 2-3 times more likely to receive CNS-acting drugs than controls. In the year following commencement of IBS therapy, patients were 2-4 times more likely than controls to be prescribed CNS-acting drugs including antidepressants (35.4% vs. 9.3%), anxiolytics (27.8% vs. 8.8%), antipsychotics (9.8% vs. 3.3%) and hypno-sedatives (32.7% vs. 11.3%; P < 0.0001). The adjusted OR (95% CI) for antidepressant, anxiolytic, hypnosedative and antipsychotic prescribing in IBS patients were 3.81 (2.79-5.20), 2.84 (2.12-3.81), 2.62 (1.91-3.60) and 2.58 (1.80-3.66), respectively.

CONCLUSIONS

Patients prescribed ongoing therapy for presumed IBS are 2-4 times more likely to be prescribed CNS-acting drugs than controls, providing evidence of psychological comorbidity in IBS.

Utilisation of antibiotic therapy in community practice

The aim of the study was to identify outpatient antibiotic consumption between Jan 2000 and Dec 2005 through analysis of the HSE-Primary Care Reimbursement Services (PCRS) database as part of the Surveillance of Antimicrobial Resistance in Ireland (SARI) project. Total antibiotic consumption on the PCRS scheme between January 2000 and December 2005 expressed in Defined Daily Dose per 1000 PCRS inhabitants per day increased by 26%. The penicillin group represents the highest consumption accounting for approximately 50% of the total outpatient antibiotic use. Total DIDs for this group increased by 25% between 2000 and 2005. Co-amoxiclav and amoxicillin account for 80% of the total consumption of this group of anti-infectives. With the exception of aminoglycosides and sulfonamides which demonstrated a decrease in DID consumption of 47% and 8% respectively, all other groups of anti-infectives had an increase in DID consumption of greater than 25% during the study period. Antibiotic prescribing data is a valuable tool for assessing public health strategies aiming to optimise antibiotic prescribing.

Impact of an acute medical admission unit on hospital mortality: a 5-year prospective study

AIM

To determine the impact of the introduction of an acute medical admission unit (AMAU) on all-cause hospital mortality in unselected patients undergoing acute medical admission to a teaching hospital.

DESIGN

Analysis of data recorded in the hospital in-patient enquiry (HIPE) system relating to all emergency medical patients admitted to St James's Hospital (SJH), Dublin between 1 January 2002 and 31 December 2006.

METHODS

The reference year was 2002, during which patients were admitted to a variety of wards under the care of a named consultant physician. In 2003, two centrally located wards were re-configured to function as an AMAU, and all emergency medical patients were admitted to this unit following emergency department evaluation. Hospital mortality was obtained from a database of deaths occurring during this period and linked to HIPE data.

RESULTS

Following the introduction of the AMAU process, all-cause hospital mortality decreased from 12.6% in 2002 to 7.0% in 2006 (P < 0.0001), representing a 44.4% relative reduction during the course of the 5-year observation period (P < 0.0001). The Odds ratio (95% confidence interval) for all-cause mortality in 2006 compared with 2002 was 0.28 (0.23, 0.35). This effect was powerfully independent of other covariates, including Charlson co-morbidity and illness severity score (APACHE II), in binary logistic regression analysis and was observed across a wide cross-section of diagnostic groups.

CONCLUSION

The introduction of an AMAU significantly improved all-cause hospital mortality in acute unselected medical patients. The delivery of Acute Medicine may be enhanced by structural reform with emphasis on focus and volume. Prospective studies validating similar models elsewhere should be explored.

Epidemiology and economics of statin use

In 2006 the State supported the purchase of statins by some Euro 120 million for some 466,366 patients. While about 50% is for secondary prevention of heart disease a disproportionate number of women are receiving treatment for primary prevention. For proprietary agents the monthly cost was largely explained by price and dosage (mg/day) and the average varied from Euro 29.2 for rosuvastatin (11 mg), Euro 38.2 simvastatin (21 mg), Euro 39.1 atorvastatin (19 mg), Euro 42.7 pravastatin (21 mg) and Euro 31.8 for generic prava/simvastatin (21 mg). Generic substitution for pravastatin and simvastatin would save Euro 6.4m. Applying the drug prices corresponding in the United Kingdom would result in savings of some Euro 35m per annum. While the increasing use of statins is justified on cost benefit/analysis considerable savings could be made through choice of the more potent statins, a greater use of generics and a flatter dose price structure.

The utilisation and expenditure of medicines for the prophylaxis and treatment of osteoporosis

The elderly population represent the fastest growing age-group and the incidence of osteoporotic related fractures is likely to increase with continued ageing of the population. This study determined the prescribing patterns on the Health Services Executive's (HSE) Primary Care Reimbursement Services Scheme (HSE-PCRS) of medicines dispensed for the prophylaxis and treatment of osteoporosis in Ireland. The HSE - PCRS prescription databases were analysed for the years 2004/2005. Approximately 65% of patients (total 60,000) were dispensed either Alendronate (Fosamax once weekly) or Risedronate (Actonel once weekly). The majority of the patients (69.3%) were over 70 years. The study identified that the longer a patient was prescribed prednisolone the greater the likelihood of subsequently being prescribed a bisphosphonate. Approximately 50% of patients on long-term steroids did not receive prophylaxis for osteoporosis. There were low levels of co-prescribing (2.5%) with potentially interacting drugs. Levels of co-prescribing with proton pump inhibitors was 22%.

Effect of antiretroviral therapy and hepatitis c co-infection on changes in lipid levels in HIV-Infected patients 48 weeks after initiation of therapy

Hepatitis C virus (HCV) commonly co-infects HIV-infected individuals. Antiretroviral therapy (ART) is associated with elevated serum lipid levels, and HCV infection is associated with low serum lipid levels. Fasting lipid levels were investigated in 1,434 ART-naïve HIV-infected people participating in the AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trials (ALLRT) protocol who prospectively initiated ART with 3 agents. Subjects with elevated liver-associated enzymes (>5 x ULN) were excluded. Demographics, body mass index, HCV status, CD4 cell count, HIV RNA, liver enzymes, lipid levels, and glucose were assessed before and following 48 weeks of ART. HCV-positive subjects (n = 160; 11%) were older, more likely to be Black, have a history of intravenous drug use (IDU), have higher baseline liver-associated enzyme levels than the HCV-negative group (p < .001 for each), and to have diabetes at baseline (5% vs. 2%, p = .07). Lipid levels rose in both groups following ART, and the differences were not significant except that HDL levels increased significantly more in the HCV-positive group (p = .006). In summary, HCV infection did not appear to provide significant protection against ART-induced hyperlipidemia in this cohort of HIV-infected subjects prospectively enrolled in ART trials, although HDL levels rose to a greater degree.

Adherence to clinical guidance in the prescribing of oral antithrombotic medication in patients with atrial fibrillation

BACKGROUND

Atrial fibrillation is the commonest cardiac rhythm disturbance and is an independent risk factor for stroke; however, use of oral antithrombotic therapy is reported to be suboptimal in clinical practice.

AIM

The aim of the study was to evaluate the prescribing rates of oral antithrombotic therapy in patients with atrial fibrillation to determine if prescribing patterns reflected published clinical guidance.

METHOD

Patients with atrial fibrillation, admitted to hospital over a 12-week period were identified and their antithrombotic therapy regimen was analysed using statistical methods.

RESULTS

Although 87/100 patients identified were prescribed OAT, the regimen was suboptimal in 35 patients. Patients aged 75 years and older were more likelyto be receiving suboptimal oral antithrombotic treatment compared with younger patients

CONCLUSIONS

The benefits and suitability of oral antithrombotic therapy for patients of all ages need to be more comprehensively communicated to prescribers.

Impact of the ATAC trial on prescribing of hormonal therapy in breast cancer

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Background: The arimidex, tamoxifen, alone or in combination (ATAC) trial recommended use of anastrazole over tamoxifen as initial adjuvant hormonal therapy of early breast cancer in postmenopausal women. The aim of this study was to investigate the impact of the publication of the ATAC trial in December 2004 on subsequent prescribing of hormonal therapy to Irish women =55 years old. Methods: The Irish HSE-PCRS pharmacy claims database was used to identify all women =55 years old, commenced on tamoxifen or an aromatase inhibitor as initial hormonal therapy, between July 2000 and June 2006. A segmented regression analysis of an interrupted time series was used to detect changes in the trend and level of anastrazole prescribing after publication of the ATAC trial in December 2004 and the prior updates in November 2003 and June 2002 (presented December 2001). β coefficients and 95%CI are presented where appropriate. The absolute change in anastrazole prescribing and 95%CI are also calculated for selected months. Statistical analysis was performed using SAS version 9.1. Significance at p<0.05 is assumed. Results: A cohort of 7,604 women =55 years old, commenced on initial hormonal therapy, was identified from the HSE-PCRS database, 2,206 (29%) of these women were prescribed anastrazole. In the month following publication of the final results of the ATAC trial there was a 17.6% (95% CI 10.8%, 24.5%) absolute increase in anastrazole prescribing. This represented a statistically significant increase in the level of prescribing (level change β=18.1 95% CI 11.3, 24.9 p<0.0001). There was also a significant change in anastrazole prescribing trend after presentation of the first ATAC update (slope change β=0.98 95% CI 0.59, 1.37 p<0.0001). Conclusion: The publication of the final ATAC trial data resulted in a significant increase in the prescribing of anastrazole. This is objective evidence that oncologists respond rapidly to clinical trial results. It is unclear whether the significant increase in anastrazole prescribing after the first ATAC update is an appropriate response to an interim analysis.

No significant financial relationships to disclose.

Relationship between the intensity of physical activity, inactivity, cardiorespiratory fitness and body composition in 7-10-year-old Dublin children

OBJECTIVE

To investigate the relationships between the time spent in specific intensities of activity and inactivity, cardiorespiratory fitness and body composition in children.

METHODS

A cross-sectional study was conducted in a random sample of schools. Height, weight and waist circumference were measured in 224 children aged 7-10 years. Cardiorespiratory fitness was estimated by the 20 m multistage running test, and physical activity was measured over 4 days by the RT3 (a triaxial accelerometer). Time each day spent in moderate and vigorous intensities of activity was calculated.

RESULTS

Twelve schools agreed to participate in the study. Body composition and fitness data were obtained for 224 children and activity data for 152 children. Boys were found to take part in about twice as much vigorous and hard activity as girls (mean (95% confidence interval) 64.3 (53.2 to 75.4) min in boys compared with 37 (33.1 to 40.9) min in girls; p<0.001). In boys there was significant difference between those defined as normal, overweight and obese in the time spent in vigorous activity (p<0.05), but no such difference was found in girls. A significant negative correlation between waist circumference and time spent in vigorous activity (r = -0.31, p<0.05) was found in boys but not in girls. Time spent sedentary was positively correlated with waist circumference in boys (r = 0.33, p<0.01) but not in girls. In both boys and girls there were significant negative correlations between fitness and both body mass index (r = -0.274, p<0.001) and waist circumference (boys: r = -0.503, p<0.01; girls: r = -0.286, p<0.01).

CONCLUSION

In boys, body composition was inversely related to fitness and to vigorous activity and was positively related to inactivity. In girls, body composition was related to fitness but not to specific components of physical activity.

Lung cancer and urban air-pollution in Dublin: a temporal association?

In 1990, the sale, marketing and distribution of bituminous coal, primarily used for domestic heating, were banned across Dublin. This study exploits the potential of a 'natural experiment' to assess a temporal association between adjusted annual lung cancer death rates and the changing annual mean urban air-pollution concentrations in Dublin from 1981 to 2000. Annual mean 'black smoke' (BS) concentration was used as an indicator variable for the urban air-pollution mixture. Log-linear Poisson regression model (with an offset) was used to estimate adjusted rate ratios of lung cancer death rates between two periods (1981-1990 and 1991-2000) relative to the year 1990. A significant (p<0.0001) two-third decline in BS concentration (28.2 microg/m(3)) was seen between the two periods [pre-ban (46.4 microg/m(3)) vs. post-ban (18.2 microg/m(3))]. Relative to 1990 (rate ratio= 1 ), a slightly greater decline (2%) in death rates was achieved in the pre-ban period (1981-1990) when mean annual BS concentrations were very high, but a lower decline (1%) was seen in the post-ban period (1991-2000) corresponding to very low mean annual BS concentrations. In other words, a further fall in adjusted rates in lung cancer was achievable both in the pre-ban and the post-ban periods when simultaneously controlling for BS and smoking. A temporal association thus observed between lung cancer death rates and the changing BS concentrations suggests that control of particulate air-pollution could further reduce lung cancer rates, irrespective of smoking patterns.

Impact of Helicobacter pylori on the management of dyspepsia in primary care

BACKGROUND

It is unclear what impact Helicobacter pylori infection has had on the management of dyspepsia in primary care and to what extent published guidelines on H. pylori are implemented in routine clinical practice.

AIM

To assess the impact of H. pylori infection on the management of dyspepsia in primary care.

METHODS

Patients referred by primary care doctors to an open-access 13-carbon urea breath test service over a 2-year period for their first urea breath test were included in the study. Individual breath results were linked with data on prescribing obtained from the General Medical Services prescription database.

RESULTS

Of 805 patients, 374 (47%) had a positive urea breath test and 431 (54%) a negative urea breath test. Of positive urea breath test patients, only 245 (64%) were prescribed eradication therapy in the 3 months after the breath test and only 43% were referred back for re-testing. In the year after the urea breath test, there was a significant fall in prescribing of antisecretory therapy which was greatest in the patients who received H. pylori therapy (P < 0.001).

CONCLUSIONS

There appears to be under and inappropriate treatment of H. pylori infection in primary care, and a low rate of re-testing after eradication, indicating that current guidelines are not well implemented in practice.

The population mortality benefits of maximizing the number of eligible patients receiving appropriate cardiology treatments in Ireland

BACKGROUND

Coronary heart disease (CHD) mortality rates have been decreasing in many industrialized countries since the 1980s. Up to half this decrease can be attributed to evidence-based medical and surgical cardiology interventions. However, recent studies suggest that modern cardiology treatment uptake levels remain disappointingly low in many patient categories.

AIM

To determine the potential for further reductions in CHD mortality in Ireland from increasing the number of eligible patients receiving cardiology treatments.

METHODS

A previously validated, cell-based IMPACT CHD mortality model was used to integrate large amounts of data describing CHD patient numbers, and the effectiveness and uptake levels of specific medical and surgical treatments. The CHD mortality reductions potentially achievable through the increased use of specific treatments were then calculated, stratified by age and gender and tested using sensitivity analyses.

RESULTS

In 2000, medical and surgical coronary disease treatments together prevented or postponed approximately 1950 CHD deaths in the adult population aged 25-84. However, increasing treatment levels to reach 80% of eligible patients might have prevented or postponed a further 2280 CHD deaths in 2000 (minimum estimate 860, maximum estimate 4000). The biggest gain was from maximizing the treatment uptake of eligible heart failure patients, followed by those receiving statins and secondary prevention therapies.

DISCUSSION

Many eligible patients are currently not receiving appropriate evidence-based treatments that would reduce CHD mortality and morbidity. Our results suggest that increasing cardiology treatment uptake in Ireland could at least double the current therapeutic reduction in CHD mortality.

Emergency department census of patients awaiting admission following reorganisation of an admissions process

OBJECTIVES

To determine the impact of reorganisation of an acute admissions process on numbers of people in the emergency department (ED) awaiting admission to a hospital bed in a major teaching hospital.

METHODS

We studied all emergency medical patients admitted to St James' Hospital, Dublin, between 1 January 2002 and 31 December 2004. In 2002, patients were admitted to a variety of wards from the ED when a hospital bed became available. In 2003, two centrally located wards were reconfigured to function as an acute medical admissions unit (AMAU) (bed capacity 59), and all emergency patients were admitted directly to this unit from the ED (average 15 admissions per day). The maximum permitted length of stay on the AMAU was 5 days. We recorded the number of patients in the ED, who were awaiting the availability of a hospital bed, at 0700 and 1700 on the days of recording during the 36 month study period.

RESULTS

The impact of the AMAU reduced overall hospital length of stay from 7 days in 2002 to 5 days in 2003 and 2004 (p<0.0001). The median number of patients waiting in the ED for a hospital bed reduced from 14 in 2002 to 9 in 2003 and 8 in 2004 (p<0.0001). While age and sex of patients did not differ over the years, the factors that independently contributed to the number of patients awaiting admission were the day of the week, the month of the year, and and the extent of the comorbidity index on the previous day's intake (p<0.0001).

CONCLUSIONS

This study found that reorganisation of a system for acute medical admissions can significantly impact on the number of patients awaiting admission to a hospital bed, and allow an ED to operate efficiently and at a level of risk acceptable to patients.

Prescribing for patients with diabetes in the community drug schemes

The aim of the study was to examine the management of diabetes patients particularly in relation to secondary preventative therapies within the community drug schemes across the health board regions in Ireland. The study population was identified using two national primary care prescribing databases from the Long Term Illness (LTI) and General Medical Services (GMS) scheme for 2003. 65,593 patients were identified as having 'treated' diabetes. Logistic regression was used to predict the likelihood of receiving secondary preventative therapies by region and drug scheme using adjusted odds ratios (ORs) and 95% confidence intervals (CI). The proportion of diabetes patients in each drug scheme with Ischaemic Heart Disease (IHD) was also calculated. Prevalence of 'treated' diabetes was calculated for each health board also. Regional and scheme-based variations within each region exist in the prescribing of secondary preventative therapies after adjustment for IHD rates. Prevalence of treated diabetes varied between regions from 1.5% in the Eastern region to 2.2% in the Southern region. While the location of specialised diabetes clinics may be a contributing factor, inequalities in prescribing across regions within the drug schemes are apparent.

Effect of clinical trial publicity on HRT prescribing in Ireland

OBJECTIVE

To evaluate the effect of publicity surrounding the Women's Health Initiative (WHI) and Million Women (MW) studies on prescribing of all hormone replacement therapy (HRT) preparations and bisphosphonates in Ireland.

METHODS

The General Medical Services (GMS) prescription database was used to identify the study population. Prescriptions were identified for HRT and bisphosphonate preparations [using WHO Anatomical Therapeutic Chemical (ATC) classification codes] in female patients aged 45-69 years in Ireland during a 4-year study period (January 2001-December 2004). Prescription rates were calculated monthly. Prevalence and incidence of HRT use was examined.

RESULTS

There was a significant reduction in prevalence for all HRT preparations following the WHI trial (test for change in trend p<0.0001), which persisted after the MW study. The incidence of combined oestrogen/progestogen HRT declined after the WHI trial (test for change in trend p=0.004). Bisphosphonate prescribing showed a significant increase throughout the study period (p<0.0001).

CONCLUSION

The findings suggest that coverage surrounding the publication of clinical trials appears to have had a negative impact on the rate of HRT prescribing. The findings regarding the coincident increase in use of bisphosphonates may suggest that prescribers and users were less likely to regard HRT as an appropriate therapy in the management of osteoporosis for some time before guidance was issued by the regulatory authorities.

Socioeconomic influences on benzodiazepine consumption in an Irish Region

Misuse of prescription sedatives is a significant problem for addiction treatment services. The aim of this study was to examine the prescribing of diazepam in disadvantaged Irish communities, and to identify factors which may predict diazepam consumption in that population. We examined prescribing trends for those aged 16-69 years in 2002 in a region of the state-funded General Medical Services Scheme. Material deprivation was based on the 2002 Small Area Health Research Unit (SAHRU) deprivation index. The average defined daily dose (DDD) was calculated and logistic regression analysis was used to predict diazepam use by age, gender and deprivation index. Results showed that patients living in the most-deprived areas were more likely to receive diazepam than patients living in the least-deprived areas (OR = 1.21, 95% CI 1.15-1.27). Female patients living in the most-deprived areas were also more likely to receive diazepam than those living in the least-deprived areas (OR = 1.36, 95% CI 1.18-1.57). It is concluded that there is a pattern of higher diazepam prescribing in areas of greatest deprivation, where prescription sedatives play a complex role within troubled families.