***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Objective To examine the risk of non-fatal idiopathic venous thromboembolism in current users of a combined oral contraceptive containing drospirenone  , relative to current users of preparations containing levonorgestrel .  Design Nested case-control study . Setting UK General Practice Research Data base . Participants Women aged 15 - 44 years without major risk factors for venous thromboembolism who started a new episode of use of an oral contraceptive containing 30 µg oestrogen in combination with either drospirenone or levonorgestrel between May 2002 and September 2009 . Cases were women with a first diagnosis of venous thromboembolism ; up to four controls , matched by age , duration of recorded information , and general practice , were r and omly selected for each case . Main outcome measures Odds ratios and 95 % confidence intervals estimated with conditional logistic regression ; age adjusted incidence rate ratio estimated with Poisson regression . Results 61 cases of idiopathic venous thromboembolism and 215 matched controls were identified . In the case-control analysis , current use of the drospirenone contraceptive was associated with a threefold higher risk of non-fatal idiopathic venous thromboembolism compared with levonorgestrel use ; the odds ratio adjusted for body mass index was 3.3 ( 95 % confidence interval 1.4 to 7.6 ) . Subanalyses suggested that referral , diagnostic , first time user , duration of use , and switching biases were unlikely explanations for this finding . The crude incidence rate was 23.0 ( 95 % confidence interval 13.4 to 36.9 ) per 100 000 woman years in current users of drospirenone and 9.1 ( 6.6 to 12.2 ) per 100 000 woman years in current users of levonorgestrel oral contraceptives . The age adjusted incidence rate ratio was 2.7 ( 1.5 to 4.7 ) . Conclusions These findings contribute to emerging evidence that the combined oral contraceptive containing drospirenone carries a higher risk of venous thromboembolism than do formulations containing levonorgestrel OBJECTIVE To determine the incidence of venous thromboembolism ( VTE ) , comprising deep vein thrombosis ( DVT ) and pulmonary embolism ( PE ) , in a well defined urban community broadly representative of the Australian population in terms of age , sex and ethnic distribution . DESIGN , SETTING AND PARTICIPANTS A prospect i ve , community-based study conducted over a 13-month period from 1 October 2003 to 31 October 2004 . People in a population of 151 923 permanent residents of north-eastern metropolitan Perth , Western Australia , who developed VTE during the study period were identified prospect ively and retrospectively through multiple overlapping sources . MAIN OUTCOME MEASURE Number of cases of symptomatic , objective ly verified DVT and PE . RESULTS 137 patients had 140 VTE events ( 87 DVT and 53 PE ) . The crude annual incidence per 1000 residents was 0.83 ( 95 % CI , 0.69 - 0.97 ) for VTE , 0.52 ( 95 % CI , 0.41 - 0.63 ) for DVT , and 0.31 ( 95 % CI , 0.22 - 0.40 ) for PE . The annual incidence per 1000 residents after age adjustment to the World Health Organization World St and ard Population was 0.57 ( 95 % CI , 0.47 - 0.67 ) for VTE , 0.35 ( 95 % CI , 0.26 - 0.44 ) for DVT , and 0.21 ( 95 % CI , 0.14 - 0.28 ) for PE . CONCLUSION If the crude annual incidence of VTE in this area of metropolitan Perth is externally valid , then VTE affects about 17 000 Australians annually . Future studies of trends in VTE incidence will be needed to measure the effectiveness of VTE prevention strategies OBJECTIVES The study was conducted to compare risks of adverse cardiovascular and other events associated with the use of drospirenone (DRSP)-containing oral contraceptives ( OCs ) and other OCs .  METHODS AND MATERIAL S The European Active Surveillance study ( EURAS ) was a multinational , prospect i ve , noninterventional cohort study of new users of DRSP , levonorgestrel ( LNG ) and other progestin-containing OCs .  Semiannual follow-up was based on mailed question naires , with additional follow-up procedures when needed . RESULTS Overall , 58,674 women were followed for 142,475 women-years of observation . Loss to follow-up was 2.4 % . Serious adverse and fatal events were rare , and rate ratios were close to unity ( 1.0 ) . Cox regression analysis of cardiovascular outcomes yielded hazard ratios for DRSP-containing vs. LNG-containing and other OCs of 1.0 and 0.8 ( upper 95 % confidence limits , 1.8 and 1.3 ) for venous , and 0.3 and 0.3 ( upper 95 % confidence limits , 1.2 and 1.5 ) for arterial thromboembolism , respectively . CONCLUSIONS Risks of adverse cardiovascular and other serious events in users of a  DRSP-containing OC  are similar to those associated with the use of other OCs OBJECTIVE To determine current  contraceptive management by general practitioners in Australia . DESIGN , SETTING AND PARTICIPANTS Analysis of data from a r and om sample of 3910 Australian GPs who participated in the Bettering the Evaluation and Care of Health ( BEACH ) survey , a continuous cross-sectional survey of GP activity , between April 2007 and March 2011 . Consultations with female patients aged 12 - 54 years that involved all forms of contraception were analysed . MAIN OUTCOME MEASURES GP and patient characteristics associated with the management of contraception ; types of contraception used ; rates of encounters involving emergency contraception . RESULTS Increased age , ethnicity , Indigenous status and holding a Commonwealth Health Care Card were significantly associated with low rates of encounters involving management of contraception . The combined oral contraceptive pill was the most frequently prescribed method of contraception , with moderate prescription of  long-acting reversible contraception ( LARC )  , especially among women aged 34 - 54 years . Rates of consultations concerned with emergency contraception were low , but involved high rates of counselling , advice or education ( 48 % ) compared with encounters for general contraception ( > 20 % ) . CONCLUSION A shift towards prescribing LARC , as recommended in clinical guidelines , has yet to occur in Australian general practice . Better underst and ing of patient and GP perspectives on contraceptive choices could lead to more effective contraceptive use OBJECTIVES The " International Active Surveillance Study of Women Taking Oral Contraceptives " investigated the risks of short- and long-term use of an extended 24-day regimen of drospirenone and ethinylestradiol ( DRSP24d ) compared to established oral contraceptives ( OCs ) in a routine clinical setting . STUDY DESIGN Prospect i ve , controlled , noninterventional cohort study conducted in the United States and six European countries with three main cohorts : new users of DRSP24d , DRSP21d ( 21-day regimens of DRSP-containing OCs ) , and non-DRSP ( OCs without DRSP ) .  All self-reported clinical outcomes of interest ( OoI ) were vali date d via attending physicians and relevant source documents . Main OoI were serious clinical outcomes , in particular venous thromboembolism ( VTE ) . Comprehensive follow-up procedures were implemented . Statistical analyses were based on Cox regression models . Primary statistical variable was the VTE hazard ratio ( HR ) for DRSP24d vs. non-DRSP . RESULTS A total of 2285 study centers enrolled 85,109 women . Study participants were followed for 2 to 6 years , which generated 206,296 woman-years ( WY ) of observation . A low loss to follow-up of 3.3 % was achieved . DRSP24d , DRSP21d , non-DRSP and levonorgestrel-containing OCs ( LNG ) showed similar incidence rates of venous and arterial thromboembolism , fatal outcomes , cancer , severe depression and other serious adverse events . VTE incidence rates for DRSP24d , DRSP21d , non-DRSP and LNG were 7.2 , 9.4 , 9.6 and 9.8 VTE/10,000 WY , respectively . Adjusted HRs for DRSP24d vs. non-DRSP and DRSP24d vs. LNG were 0.8 [ 95 % confidence interval ( CI ) , 0.5 - 1.3 ] and 0.8 ( 95 % CI , 0.4 - 1.5 ) . CONCLUSION DRSP24d , DRSP21d , non-DRSP and LNG use was associated with similar risks of serious adverse events , and particularly VTE , during routine clinical use . IMPLICATION STATEMENT The 24-day regimen of drospirenone-containing combined OCs is associated with similar risks of venous and arterial thromboembolism , fatal outcomes , cancer , severe depression and other serious adverse events compared to 21-day regimens of drospirenone-containing combined OCs , OCs without drospirenone and LNGs 
    Output:
    
DISCUSSION The difference in risk of VTE based on the choice of progestin in COCs is , at worst , very small in absolute terms and should not be the sole factor considered when choosing the ' right ' COC for each woman