Journals watch: Alzheimer's disease, renal stones and hip fracture

Benzodiazepine use and risk of Alzheimer's disease

BMJ 2014; 349: g5205

This case-control study strongly suggests the benzodiazepine class has an impact on memory impairment. It involved 1,796 patients with a first diagnosis of Alzheimer's disease who were followed up for at least six years before being matched with 7,184 controls on sex, age group and duration of follow-up.

The risk of Alzheimer's disease was increased by 43-51% among those who had taken benzodiazepines in the past. Risk increased with density of exposure and when long-acting benzodiazepines were used.

Further adjustment on symptoms thought to be potential prodromes for dementia, such as depression, anxiety or sleep disorders, did not meaningfully alter the results.

The authors suggest this might represent an association only, but point out that benzodiazepine use might also be an early marker of a condition associated with increased risk of dementia.

Home modifications versus falls and injury risk

The Lancet doi: 10.1016/S0140-6736(14)61006-0

Despite the considerable injury burden attributable to falls at home among the general population, few effective safety interventions have been identified.

This single-blind, cluster-RCT of households in New Zealand tested the safety benefits of home modifications, including handrails for outdoor steps and internal stairs, grab rails in bathrooms, outside lighting, edging for outdoor steps and slip-resistant surfacing for areas such as decks and porches.

By a coin toss, the 842 households identified were randomised to either an immediate refit (treatment group) or a three-year delay (control group).

After a median observation period of 1,148 days, the authors found a 26% reduction in the rate of injuries caused by falls at home per year for those exposed to the intervention.

Investigating patients with suspected renal stones

N Engl J Med 2014; 371: 1100-10

Loin to groin? Coming and going? I suspect renal colic secondary to nephrolithiasis, but where to next with radiology?

To answer this common conundrum, which has no consensus opinion, these US authors randomised 2,759 patients to one of three groups, 908 to point-of-care ultrasonography, 893 to radiology ultrasonography and 958 to CT.

The researchers found that initial ultrasonography was associated with lower cumulative radiation exposure than initial CT, without significant differences in high- risk diagnoses with complications, serious adverse events, pain scores, return emergency department visits or hospitalisation.

Orthogeriatrics for hip fracture

Med J Aust 2014; 201 (7): 409-11

A recent development is the orthogeriatric service for older patients with orthopaedic conditions, which is provided collaboratively with the treating orthopaedic team. In Australia, it is predominantly provided by geriatricians.

These authors examined the impact of orthogeriatric services on 30-day mortality and length of stay (LOS) for hip fracture patients undergoing surgery in public hospitals in New South Wales.

During the study period, there were 9,601 hip fracture cases for which surgery was carried out. Hospitals providing the services had a 6.2% 30-day mortality rate, compared with 8.4% in those that did not. The payoff was an LOS that extended from 22 to 26 days.

This work follows the model of change in the UK, where figures from the National Hip Fracture Database are broadly similar.

Microscopic haematuria and bladder cancer risk

Br J Gen Pract doi: 10.3399/bjgp14X681409

Apparently, the importance of non-visible blood has never been estimated. Having a long-established GP database has surely helped in this research. The authors performed a case-control study using UK electronic primary care medical records, including uncoded data to supplement coded records.

A total of 4,915 patients (aged ?40 years) diagnosed with bladder cancer between January 2000 and December 2009 were selected from the Clinical Practice Research Datalink and matched to 21,718 controls for age, sex and practice.

The authors found the PPV of non-visible haematuria was 1.6% in those aged ?60 years and 0.8% in those aged 40-59 years. The PPV of visible haematuria was 2.8% and 1.2% for the same age groups. They mention that a recent patient study suggests 90+% would want investigation at a 1% risk.

• Dr Palmer is a former Hampshire GP now working in Australia and a member of our team who regularly review the journals

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