Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how well a test can classify subjects who truly have the outcome of interest. Specificity, which denotes the proportion of subjects correctly given a negative assignment out of all subjects who are actually negative for the outcome, indicates how well a test can classify subjects who truly do not have the outcome of interest. Positive predictive value reflects the proportion of subjects with a positive test result who truly have the outcome of interest. Negative predictive value reflects the proportion of subjects with a negative test result who truly do not have the outcome of interest. Sensitivity and specificity are inversely related, wherein one increases as the other decreases, but are generally considered stable for a given test, whereas positive and negative predictive values do inherently vary with pre-test probability (e.g., changes in population disease prevalence). This article will further detail the concepts of sensitivity, specificity, and predictive values using a recent real-world example from the medical literature.

Blinding mitigates several sources of bias which, if left unchecked, can quantitively affect study outcomes. Blinding remains under-utilized, particularly in non-pharmaceutical clinical trials, but is often highly feasible through simple measures. Although blinding is generally viewed as an effective method by which to eliminate bias, blinding does also pose some inherent limitations, and it behooves clinicians and researchers to be aware of such caveats. This article will review general principles for blinding in clinical trials, including examples of useful blinding techniques for both pharmaceutical and non-pharmaceutical trials, while also highlighting the limitations and potential consequences of blinding. Appropriate reporting on blinding in trial protocols and manuscripts, as well as future directions for blinding research, will also be discussed.

To raise awareness on nocturia disease burden and to provide simplified aetiologic evaluation and related treatment pathways. A multidisciplinary group of nocturia experts developed practical advice and recommendations based on the best available evidence supplemented by their own experiences. Nocturia is defined as the need to void ≥1 time during the sleeping period of the night. Clinically relevant nocturia (≥2 voids per night) affects 2%-18% of those aged 20-40 years, rising to 28%-62% for those aged 70-80 years. Consequences include the following: lowered quality of life; falls and fractures; reduced work productivity; depression; and increased mortality. Nocturia-related hip fractures alone cost approximately €1 billion in the EU and $1.5 billion in the USA in 2014. The pathophysiology of nocturia is multifactorial and typically related to polyuria (either global or nocturnal), reduced bladder capacity or increased fluid intake. Accurate assessment is predicated on frequency-volume charts combined with a detailed patient history, medicine review and physical examination. Optimal treatment should focus on the underlying cause(s), with lifestyle modifications (eg, reducing evening fluid intake) being the first intervention. For patients with sustained bother, medical therapies should be introduced; low-dose, gender-specific desmopressin has proven effective in nocturia due to idiopathic nocturnal polyuria. The timing of diuretics is an important consideration, and they should be taken mid-late afternoon, dependent on the specific serum half-life. Patients not responding to these basic treatments should be referred for specialist management. The cause(s) of nocturia should be first evaluated in all patients. Afterwards, the underlying pathophysiology should be treated specifically, alone with lifestyle interventions or in combination with drugs or (prostate) surgery.

The literature on prevention and therapy of urinary tract infection (UTI) in patients with spinal cord injury (SCI) was reviewed using 3 levels of evidence. Antibiotic therapy is only indicated in symptomatic bacteriuria or in symptomatic exacerbations of chronic UTI. During the acute phase of a SCI, UTI's are more prevalent and bacteria are different and more resistant to antibiotics compared with the chronic phase of SCI. In SCI in general, routine screening urine cultures are not valuable as a high species turn over is seen. Intermittent catheterisation, tapping or Crédé manoeuvre coincide significantly with lower frequency of UTI compared to permanent catheter drainage. No measures are proven efficient in the long term in prevention of bacteriuria or UTI. Methenamine salts are perhaps useful in the prevention of UTI but not in patients with a permanent catheter (level III). Antibiotic prophylaxis was found useful in reducing asymptomatic bacteriuria but not in the prevention of symptomatic infections (level I). However, during prophylaxis a doubling of antibiotic resistance was found. In patients with augmented bladder antibiotic prophylaxis is useless (level II). In chronic SCI the first choice antibiotics are nitrofurantoin or trimethoprim, the second choice are fluoroquinolones (level III) whereas in acute SCI a higher resistance profile to antibiotics is frequent and therefore fluoroquinolones or cefuroxime are suggested (level III). There is no consensus in the literature but we suggest 5 days of antibiotic treatment in UTI during chronic SCI without fever, 7 days in acute SCI without fever and a minimum of 14 days in patients with UTI and fever (level III).