Changes

July 2023 — reviewed. A literature search was conducted in July 2023 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomized controlled trials (RCTs) published since the last revision of this topic. No major changes to core recommendations have been made, but the advice on screening for sexually transmitted infections and the use of intravaginal gels has been updated based on the manufacturers' recommendations. There have been minor changes made to the structure of the topic.

Update

Goals

To support primary healthcare professionals to:

• Recognize the symptoms and signs of bacterial vaginosis (BV).
• Use further investigations as appropriate to confirm or refute the diagnosis of BV.
• Treat suspected or confirmed BV appropriately in primary care.
• Appropriately manage persistent or recurrent BV.

Outcome measures

Audit criteria

QOF indicators

QIPP - Options for local implementation

NICE quality standards

Statements in the Quality Standard Sexual Health from the National Institute of Health and Care Excellence (NICE) which may be relevant to primary care and to this topic include:

• People are asked about their sexual history at key points of contact.
• People identified as being at risk of sexually transmitted infections have a discussion about prevention and testing.
• People diagnosed with a sexually transmitted infection are supported to notify their partners.

[NICE, 2022a]

What is it?

• Bacterial vaginosis (BV) is a dysbiosis of the vagina, characterized by an overgrowth of predominantly anaerobic organisms (such as Gardnerella vaginalis, Prevotella species, Mycoplasma hominis, and Mobiluncus species) and a loss of lactobacilli. The vagina loses its normal acidity, and vaginal pH increases to greater than 4.5.
• BV is not generally regarded as a sexually transmitted infection; however, the prevalence is higher amongst sexually active women (than non-sexually active women), and it is considered by some experts to be 'sexually associated'.

[BASHH, 2012; BASHH, 2013; Sherrard, 2018; Coudray, 2020; CDC, 2021]

What factors contribute to the development of bacterial vaginosis?

• The exact aetiology and trigger for bacterial vaginosis (BV) is unknown, but symptoms are thought to appear when the vaginal pH raises following the loss of Lactobacilli [Abou Chacra, 2022]. There is no specific aetiological agent, and so rather than being considered as a sexually transmitted infection (STI), it is often termed a 'dysbiosis', a change to the usual balance in the vaginal microbiome [Coudray, 2020; Lev-Sagie, 2022].
• Factors that increase the risk of developing BV include [BASHH, 2013; Sherrard, 2018; CDC, 2021]  [Abou Chacra, 2022; Lev-Sagie, 2022]:
  • Being sexually active — BV is not considered an STI, but being sexually active or having concurrent STIs increases the risk of developing BV. It is much less common in women who have never been sexually active.
  • Having multiple male sexual partners.
  • Female partners.
  • Sexual relationships with more than one person.
  • Recent change in sexual partner.
  • Certain sexual behaviours may increase risk such as anal and oral intercourse followed by vaginal penetration, and in women who have sex with women, receptive oral sex, and the use and sharing of unwashed sex toys [Forcey, 2015].
  • Not using condoms and menstruation. Semen and menstruation are linked to alkaline vaginal pH.
  • Douching.
  • Seropositivity for herpes simplex virus 2.
  • Presence of a copper intrauterine contraceptive device.
  • Cigarette smoking.
  • Genital hygiene (not washing vaginal region, infrequent change of underwear.)
  • Ethnicity — BV is more prevalent in Black women (45–55%) than in Caucasian women (5–15%) [Sherrard, 2018].
• Factors which reduce the risk of developing BV include [CDC, 2021]: 
  • Circumcised partner.
  • Consistent condom use.
  • Hormonal contraception may be protective — a systematic review and meta-analysis found that combined hormonal contraception and progesterone-only contraception are associated with a reduction in the prevalence and incidence of BV [Vodstrcil, 2013].

How common is it?

• Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in women of childbearing age, but may also be encountered in post-menopausal women [BASHH, 2012; BMJ Best Practice, 2023].
• Globally, prevalence is high, ranging from 23 to 29% of women in the general population with significant variation by geographical region and race [Peebles, 2019].
• Reported prevalence rates include 5% in a group of asymptomatic college students, 12% in pregnant women attending an antenatal clinic in the UK, and 30% in women undergoing termination of pregnancy [BASHH, 2012]. It is more prevalent in Black women (45–55%) than in Caucasian women (5–15%) [Sherrard, 2018].
• Women who have sex with women are at increased risk for BV because they share similar lactobacillary types and are more likely to have concordant vaginal flora patterns [Sherrard, 2018].
• The prevalence of BV is higher amongst sexually active women than non-sexually active women, although it is not generally regarded as a sexually transmitted infection [Sherrard, 2018; CDC, 2021].

What are the complications?

• Women with bacterial vaginosis (BV) are at increased risk of acquiring sexually transmitted infections (STIs) [BASHH, 2013; Sherrard, 2018; Peebles, 2019].
  • Women with BV have a 2-fold increased risk of acquiring HIV compared with women without BV, and HIV-positive women with BV have a 3-fold risk of transmitting HIV [Sherrard, 2018].
  • Women with BV also have a 1.5 to 2-fold risk of acquiring chlamydia and gonorrhoea, a 9-fold risk of trichomoniasis, and a 2-fold risk of herpes simplex virus (HSV) type 2 compared with women without BV [Sherrard, 2018].
  • A prospective study of women with clinically suspected pelvic inflammatory disease (PID) reported a significant association between the presence of BV-associated bacteria and the presence of endometritis and recurrent PID [Haggerty, 2016; Sherrard, 2018].
  • There may be a link between acquiring human papillomavirus (HPV) and the development of cervical cancer [Brusselaers, 2019; Norenhag, 2020].
• BV is also associated with several obstetric and gynaecologic complications, including [BASHH, 2012]   [BASHH, 2013; Brocklehurst, 2013; Sherrard, 2018; Peebles, 2019; NICE, 2021]:
  • Late miscarriage.
  • Pre-term labour and delivery.
  • Pre-term premature rupture of membranes.
  • Spontaneous abortion.
  • Low birthweight baby.
  • Postpartum endometritis.
  • Post caesarean delivery wound infections.
  • Post-surgical infections.
  • Subclinical PID.
• Recurrence of BV is common.
  • Reported recurrence rates are variable, but may be up to 23% at one month after treatment, up to 43% at three months, and up to 58% at twelve months, with one study reporting recurrence rates up to 80% within nine months [Sherrard, 2018; Coudray, 2020].
  • This seems to reflect a failure of the normal lactobacilli to re-establish dominance and a re-emergence of the bacteria associated with BV [BASHH, 2013].

What questions should I ask a woman with suspected bacterial vaginosis?

• Take a history.
  • Ask about the symptoms experienced (if any).
    • Approximately 50% of women with bacterial vaginosis (BV) are asymptomatic.
    • When symptoms are present, BV is characterized by a fishy-smelling, thin, grey/white homogeneous discharge that is not associated with itching or soreness.
    • Check for associated symptoms which might indicate the presence of other pathology (such as dysuria, genital skin problems, abnormal vaginal bleeding, dyspareunia, and abdominal pain.)
  • Also ask about:
    • The duration and severity of symptoms, and any exacerbating factors, such as after intercourse or during the menstrual cycle. 
    • Any treatments tried (prescription or over-the-counter) and their effects.
    • The presence of contributing factors, including smoking history, the use of vaginal products, such as douches, deodorant, and vaginal washes, and the use of antiseptics, bubble baths, or shampoos in the bath.
    • Medical history (past and present).
    • Medication history, including the use of oral or intra-uterine contraceptives.
    • Possibility of pregnancy.
    • Possibility of a foreign body (retained tampon, any other items inserted into the vagina.)
  • Take a sexual history:
    • Ask whether they are sexually active, the gender of their partner, whether they are in a committed or casual relationship, the time interval since previous sexual partner, and about the use of condoms.
    • Ask about symptoms or risk factors for blood-borne viruses in the partner(s), such as known or suspected STIs, or injecting drug use.
  • Assess the woman's risk of sexually transmitted infection (STI). Anyone who has condomless sex with new or casual partners is at risk of STI, particularly those who have frequent changes of sexual partners. Women are considered at increased risk of an STI if they are:
    • Younger than 25 years of age, or
    • Have had a new sexual partner or more than 1 sexual partner in the last 12 months, or
    • Have had a previous STI.

What examination is advised in a woman with suspected bacterial vaginosis?

• Offer examination to all people presenting with genital symptoms.
• In some cases of suspected bacterial vaginosis (BV), however, examination and investigations may be omitted and empirical treatment started without further assessment if all the following apply:
  • Symptoms are characteristic of BV (smelly thin discharge with no itching or soreness).
  • The woman does not have symptoms of other conditions causing vaginal discharge (such as itching, soreness, abnormal vaginal bleeding, blood-stained discharge, or pelvic pain).
  • The woman is at low risk of an STI.
  • Symptoms have not developed pre or post a gynaecological procedure.
  • The woman is not postnatal or post miscarriage.
  • The woman is not pre or post termination.
  • This is the first episode of suspected BV, or if recurrent, a previous episode of recognizably similar symptoms was previously diagnosed to be BV following examination.
  • The woman is not pregnant. 

• Before examining
  • Consider referring women at high risk of a sexually transmitted infection (STI) to a genito-urinary medicine (GUM) clinic or other local specialist sexual health service instead, to facilitate screening for infections and partner notification (if necessary). GUM clinics have access to more immediate, comprehensive and accurate tests and results, and have systems for partner notification. Where this is accepted and agreed, it is not appropriate to duplicate the examination and tests in general practice.
  • Obtain consent and offer a chaperone. Explain why the examination is necessary and what it will involve, giving the patient the opportunity to ask questions. Get permission for the examination and record that the patient has given it. Give the patient privacy to dress and undress and keep them covered as much as possible.
  • If an examination is indicated and permission is given, consider in advance any investigations (swabs) that might be indicated so that the right type of swabs are ready for use during the examination.

• Examination
  • Palpate the abdomen (if appropriate) to assess for tenderness or a mass (which may indicate malignancy).
  • Inspect the vulva for lesions, discharge, vulvitis, ulcers, and any other changes.
  • Consider a bimanual examination to assess for cervical or adnexal tenderness, masses and to exclude a foreign body as a cause of discharge.
  • Perform a speculum examination (except in a pregnant woman with a low-lying placenta) to visualize the cervix and vagina to look for characteristic signs of BV.
    • BV is characterized by a thin, white/grey, homogeneous coating of the vaginal walls and vulva that has a fishy odour. The characteristic appearance of the discharge is not specific for BV but supports the diagnosis. If the appearance of the discharge is not characteristic, consider other diagnoses or co-infection with candidiasis or trichomoniasis. See the CKS topics on Candida - female genital and Trichomoniasis for more information.
  • Whilst examining, take a sample of the discharge for investigation. For details, see the section on investigations.

What tests are needed for a woman with suspected bacterial vaginosis?

• Using a speculum, take a swab of the discharge from the lateral wall of the vagina.
• Test the pH of the discharge
  • Ideally, pH of the discharge should be ascertained at the time of the examination in order to make the diagnosis of bacterial vaginosis (BV), and to help distinguish between BV and other causes of discharge.
  • After introducing a speculum, roll a swab anywhere on the vaginal wall to obtain a sample of the discharge. Avoid the cervix which has alkaline secretions, and also avoid the posterior fornix where cervical secretions can collect.
  • Rub the discharge from the swab onto narrow-range pH paper (pH 3.8–5.5). (Urine pH dipsticks are not suitable.)
  • Measure the pH by comparing the colour of the moist test section of pH paper against the graded standard.
  • The normal vaginal pH in a woman of childbearing age is 3.5–4.5.
  • A pH greater than 4.5 is suggestive of, but is not specific to, the diagnosis of BV; raised vaginal pH can also indicate other conditions, such as trichomoniasis.
• If the diagnosis cannot be made from history, examination and pH, send a sample of the discharge to the laboratory for Gram-staining and microscopy.
  
  • If symptoms are typical, there is no itch or soreness, and vaginal pH is greater than 4.5, there is no need for a swab for microscopy and/or culture. If testing for pH cannot be done at the time of examination, or if there is diagnostic doubt, then the discharge can be sent to the lab for microscopy which is the test of choice for BV. 
    • If not known, speak to the local lab about the preferred method to send the sample for Gram staining. Ideally, the sample of discharge is smeared onto a slide and sent in a slide box, but some labs will prepare the slide themselves from the swab.
    • Place swabs in Amies transport medium with charcoal.
    • Transport samples to the laboratory as soon as possible. If there is a delay in transportation, swabs should be refrigerated at 4°C for no longer than 48 hours.
    • Give information on the accompanying form about the history and tests required (Gram-staining and microscopy for BV and/or culture for other causes if there is recurrence or diagnostic doubt.)
    • A high vaginal swab (HVS) for culture is not routinely required for suspected BV, unless there is suspicion of upper genital tract infection, or if the woman is pregnant, postnatal, or has had recent gynaecological procedures. If an HVS is sent to the lab, give full information about the site sampled, the symptoms and history and the infection suspected, so that the relevant tests can be done.
• If the woman declines a speculum examination, a self-taken low vaginal swab of the discharge may be used for pH and microscopy.
• If the woman is at high risk of an STI:
  • Either refer to a genito-urinary medicine (GUM) clinic or test for the following:
    • Chlamydia using a vulvovaginal swab. Insert a dry swab about 2 to 3 inches into the vagina and gently rotate for 10 to 30 seconds. See the section on Testing to confirm the diagnosis in the CKS topic on Chlamydia - uncomplicated genital for more information.
    • Gonorrhoea using a vulvovaginal swab as above. See the section on Confirmation of diagnosis in the CKS topic on Gonorrhoea for more information.
    • Trichomoniasis using a swab taken from the posterior fornix at the time of the speculum examination. See the section on Diagnosis of trichomoniasis in women in the CKS topic on Trichomoniasis for more information.
    • Offer blood tests for HIV and syphilis. See the section on How to test for HIV in the CKS topic on HIV infection and AIDS and the section on Management of suspected syphilis in the CKS topic on Syphilis for more information.
  • Offer chlamydia screening to all sexually active people younger than 25 years of age, annually, or earlier if they have changed sexual partners. See the CKS topic on Chlamydia - uncomplicated genital for more information.

What else could it be?

• Differential diagnoses of bacterial vaginosis (BV) include:
  • Other infections, such as:
    • Candidiasis — characterized by a white, odourless, curdy discharge that may be associated with vulval itching and superficial soreness. See the CKS topic on Candida - female genital for more information.
    • Trichomoniasis — characterized by a fishy-smelling, yellow/green frothy discharge that may be associated with itching, soreness, and dysuria. See the CKS topic on Trichomoniasis for more information.
    • Chlamydia — often asymptomatic, but can cause purulent or mucopurulent vaginal discharge and dysuria and does not usually present with itch. pH of the discharge is 4.5 or less. See the CKS topic on Chlamydia - uncomplicated genital for more information.
    • Gonorrhoea — rarely presents with itch and is associated with pain and a purulent cervical discharge. See the CKS topic on Gonorrhoea for more information.
    • Genital herpes — may present with redness, itch, and ulceration; discharge is uncommon; and acute vulval pain is often the defining symptom. Sometimes a watery vaginal discharge may appear 7 to 11 days after primary infection. See the CKS topic on Herpes simplex - genital for more information.
    • Mixed infection — it is possible for two or more infections to coexist, such as BV together with candidiasis or trichomoniasis. Up to 10% of infections are mixed.
  • Non-infective conditions, such as:
    • Normal physiological discharge — there should be no irritation, itch, or pain, and it should not be profuse. Physiological discharge may increase suddenly in menarchal girls, varies throughout the menstrual cycle, and often occurs during pregnancy. See the CKS topic on Vaginal discharge for more information.
    • Malignancies — malignancies of the vulva, vagina, cervix, or uterine lining are rare but serious causes of vaginal discharge.
    • Cervical ectopy or polyps.
    • Fistulae.
    • Atrophic vaginitis — may cause vaginal discharge in postmenopausal women.
    • Foreign body (such as tampon) — may result in vaginal discharge.
    • Allergy — for example, to chemicals or latex. See the CKS topics on Eczema - atopic and Dermatitis - contact for more information.
    • Mechanical irritation (for example, due to lack of lubrication).

Scenario: Bacterial vaginosis in women who are not pregnant

From age 12 years onwards (Female).

Scenario: Bacterial vaginosis in women who are pregnant

From age 12 years onwards (Female).

Oral metronidazole

What do I need to know about prescribing intravaginal metronidazole?

• Do not prescribe intravaginal metronidazole gel to:
  • Women with hypersensitivity to the active drug or to any of the excipients.
• Use of intravaginal metronidazole gel is not recommended during menstruation.
• Prescribe intravaginal metronidazole gel with caution in:
  • Women with evidence of, or history of, blood dyscrasia.
  • Pregnant women — the manufacturer recommends that metronidazole should be used in pregnancy only if clearly needed as there has been no experience to date with the use of metronidazole gel in pregnant women.
  • Breastfeeding women — the manufacturer recommends that caution should be exercised when prescribing to lactating women as metronidazole is excreted in milk. It is likely that blood levels are significantly lower with topical application of metronidazole gel than oral metronidazole and adverse effects are unlikely [SPS, 2020].
• Adverse effects of intravaginal metronidazole gel are usually local and mild but side effects may include:
  • Local vaginal symptoms — itching, burning, irritation, numbness, discharge (common), vulval oedema, menstrual irregularities, vaginal spotting/bleeding (uncommon).
  • Vaginal candidiasis — known or previously undiagnosed candidiasis may worsen during treatment with metronidazole intravaginal gel and require treatment.
  • Skin and subcutaneous tissue disorders — dry skin, erythema, pruritus, skin discomfort (burning, pain of skin/stinging), skin irritation (common), urticaria (frequency unknown).
  • Nervous system disorders — headache, dizziness (common), hypothesia, paraesthesia (uncommon).
  • Gastrointestinal disorders — abdominal cramps/discomfort, vomiting, unpleasant or metallic taste/unusual feeling on the tongue (common), bloating, constipation, decreased appetite, diarrhoea, dry mouth, nausea (uncommon).
  • Psychiatric disorders — depression, insomnia (uncommon).
  • Others — urine discolouration, cramp, fatigue, irritability (uncommon), pelvic discomfort (common).
• Advise the person that:
  • If they experience any adverse effects they should discontinue use temporarily and seek medical advice.
  • Sexual intercourse during treatment with metronidazole vaginal gel should be avoided.
  • Metronidazole intravaginal gel is not recommended during menstruation.
• Drug interaction with intravaginal metronidazole gel is unlikely because absorption following cutaneous application is low. However:
  • It is not known whether topical metronidazole has an effect on prothrombin time in patients on warfarin and other coumarin anticoagulants, but the manufacturer advises this cannot be ruled out. 
  • Similarly, it is unlikely that intravaginal metronidazole gel is associated with a disulfiram-like reaction in combination with alcohol, but it cannot be excluded. No recommendation is made by the manufacturer.

[EMC, 2018]

What do I need to know about prescribing intravaginal clindamycin?

• Do not prescribe intravaginal clindamycin cream to:
  • Women previously found to be hypersensitive to preparations containing clindamycin, lincomycin, or any of the excipients.
  • Women with a history of inflammatory bowel disease or a history of antibiotic-associated colitis.
• Prescribe intravaginal clindamycin cream with caution in:
  • Pregnant women — the manufacturer advises that clindamycin is not recommended during the first trimester as there are no adequate studies in pregnant women at that stage and that clindamycin should be used in the second and third trimester of pregnancy only if clearly needed.
  • Breastfeeding women — the manufacturer recommends that a full assessment of benefits and risks should be made when considering using intravaginal clindamycin in a nursing mother.
    • It is not known if clindamycin is excreted in breast milk following vaginal administration. However, oral and parenteral clindamycin have been reported to appear in breast milk.
• Intravaginal clindamycin can be absorbed in sufficient amounts to produce systemic effects.
  • Pseudomembranous colitis can occur with most antibiotics, but it appears to be more common with clindamycin. The risk is likely to be much less with intravaginal clindamycin (than oral clindamycin) because only a small amount of the drug is absorbed. See the CKS topic on Diarrhoea - antibiotic associated for more information on pseudomembranous colitis.
  • Other possible adverse effects of intravaginal clindamycin cream include:
    • Common — Local side effects: vulvovaginal candidiasis (very common), vulvovaginitis, vulvovaginal disorder, vulvovaginal discomfort, vaginal discharge. Also abdominal cramps, back pain, constipation, diarrhoea, dizziness, dysgeusia (metallic taste), glycosuria, headaches, infections (urinary tract infection, upper respiratory tract infection), nausea, proteinuria, pruritus (non-application site), rash, vomiting.
    • Uncommon — abdominal distension, dysuria, erythema, epistaxis, flatulence, fungal infections, halitosis, hypersensitivity, pelvic pain, urticaria, vaginitis/vaginal infection, vertigo.
    • Unknown frequency — abnormal microbiological tests, dyspepsia, endometriosis, gastrointestinal disorder, hyperthyroidism; pseudomembranous colitis, skin candida.
• Advise the woman that:
  • If diarrhoea develops, she should discontinue treatment immediately and seek medical advice.
  • She should not rely on barrier methods of contraception during treatment with intravaginal clindamycin cream, or for 5 days after treatment.
    • Clindamycin intravaginal cream contains oil-based components, some of which have been shown to weaken the rubber of condoms and diaphragms, making them less effective as barrier methods of contraception or as protection from sexually transmitted infection.
• Possible drug interactions of intravaginal clindamycin cream include:
  • Neuromuscular blocking agents — systemic clindamycin may enhance the action of other neuromuscular blocking agents. The manufacturer advises it should be used with caution in patients receiving such agents.

[EMC, 2022b; BNF, 2023]

Search strategy

Scope of search

A literature search was conducted for guidelines and systematic reviews on primary care management of bacterial vaginosis.

Search dates

July 2018 - July 2023

Key search terms

Various combinations of searches were carried out. The terms listed below are the core search terms that were used for EBSCO Medline.

• (MH "Vaginosis, Bacterial") 
• AB bacterial vaginosis OR TI bacterial vaginosis 

Sources of guidelines

• National Institute for Health and Care Excellence (NICE)
• Scottish Intercollegiate Guidelines Network (SIGN)
• Royal College of Physicians
• Royal College of General Practitioners
• Royal College of Nursing
• NICE Evidence
• World Health Organization
• Guidelines International Network
• TRIP database
• Agency for Healthcare Research and Quality
• Institute for Clinical Systems Improvement
• National Health and Medical Research Council (Australia)
• Royal Australian College of General Practitioners
• British Columbia Medical Association
• Canadian Medical Association
• Alberta Medical Association
• Michigan Quality Improvement Consortium
• Singapore Ministry of Health
• National Resource for Infection Control
• RefHELP NHS Lothian Referral Guidelines
• Medline (with guideline filter)
• Driver and Vehicle Licensing Agency
• NHS Health at Work (occupational health practice)

Sources of systematic reviews and meta-analyses

• The Cochrane Library:
  • Systematic reviews
  • Protocols
  • Database of Abstracts of Reviews of Effects
• Medline (with systematic review filter)
• EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

• NIHR Health Technology Assessment programme
• The Cochrane Library:
  • NHS Economic Evaluations
  • Health Technology Assessments
• Canadian Agency for Drugs and Technologies in Health
• International Network of Agencies for Health Technology Assessment

Sources of randomized controlled trials

• The Cochrane Library:
  • Central Register of Controlled Trials
• Medline (with randomized controlled trial filter)
• EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

• Bandolier
• Drug and Therapeutics Bulletin
• TRIP database
• Central Services Agency COMPASS Therapeutic Notes

Sources of national policy

• Department of Health
• Health Management Information Consortium (HMIC)

Patient experiences

• Healthtalk
• BMJ - Patient Journeys

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

• British National Formulary (BNF)
• electronic Medicines Compendium (eMC)
• European Medicines Agency (EMEA)
• LactMed
• Medicines and Healthcare products Regulatory Agency (MHRA)
• REPROTOX
• Scottish Medicines Consortium
• Stockley's Drug Interactions
• TERIS
• TOXBASE
• Micromedex
• UK Medicines Information

Stakeholder engagement

Our policy

The external review process is an essential part of CKS topic development. Consultation with a wide range of stakeholders provides quality assurance of the topic in terms of:

• Clinical accuracy.
• Consistency with other providers of clinical knowledge for primary care.
• Accuracy of implementation of national guidance (in particular NICE guidelines).
• Usability.

Principles of the consultation process

• The process is inclusive and any individual may participate.
• To participate, an individual must declare whether they have any competing interests or not. If they do not declare whether or not they have competing interests, their comments will not be considered.
• Comments received after the deadline will be considered, but they may not be acted upon before the clinical topic is issued onto the website.
• Comments are accepted in any format that is convenient to the reviewer, although an electronic format is encouraged.
• External reviewers are not paid for commenting on the draft topics.
• Discussion with an individual or an organization about the CKS response to their comments is only undertaken in exceptional circumstances (at the discretion of the Clinical Editor or Editorial Steering Group).
• All reviewers are thanked and offered a letter acknowledging their contribution for the purposes of appraisal/revalidation.
• All reviewers are invited to be acknowledged on the website. All reviewers are given the opportunity to feedback about the external review process, enabling improvements to be made where appropriate.

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• Key stakeholders identified by the CKS team are invited to comment on draft CKS topics. Individuals and organizations can also register an interest to feedback on a specific topic, or topics in a particular clinical area, through the Getting involved section of the Clarity Informatics website.
• Stakeholders identified from the following groups are invited to review draft topics:
  • Experts in the topic area.
  • Professional organizations and societies (for example, Royal Colleges).
  • Patient organizations, Clarity has established close links with groups such as Age UK and the Alzheimer’s Society specifically for their input into new topic development, review of current topic content and advice on relevant areas of expert knowledge.
  • Guideline development groups where the topic is an implementation of a guideline.
  • The British National Formulary team.
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• Reviewers are provided with clear instructions about what to review, what comments are particularly helpful, how to submit comments, and declaring interests.

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Clarity Informatics has enlisted the support and involvement of patients and lay persons at all stages in the process of creating the content which include:

• Topic selection
• Scoping of topic
• Selection of clinical scenarios
• First draft internal review
• Second draft internal review
• External review
• Final draft and pre-publication

Our lay and patient involvement includes membership on the editorial steering group, contacting expert patient groups, organizations and individuals.

Evidence exclusion criteria

Our policy

Scoping a literature search, and reviewing the evidence for CKS is a methodical and systematic process that is carried out by the lead clinical author for each topic. Relevant evidence is gathered in order that the clinical author can make fully informed decisions and recommendations. It is important to note that some evidence may be excluded for a variety of reasons. These reasons may be applied across all CKS topics or may be specific to a given topic.

Studies identified during literature searches are reviewed to identify the most appropriate information to author a CKS topic, ensuring any recommendations are based on the best evidence. We use the principles of the GRADE and PICOT approaches to assess the quality of published research. We use the principles of AGREE II to assess the quality of published guidelines.

Standard exclusions for scoping literature:

• Animal studies
• Original research is not written in English

Possible exclusions for reviewed literature:

• Sample size too small or study underpowered
• Bias evident or promotional literature
• Population not relevant
• Intervention/treatment not relevant
• Outcomes not relevant
• Outcomes have no clear evidence of clinical effectiveness
• Setting not relevant
• Not relevant to UK
• Incorrect study type
• Review article
• Duplicate reference

Organizational, behavioural and financial barriers

Our policy

The CKS literature searches take into consideration the following concepts, which are discussed at the initial scoping of the topic.

• Feasibility
  • Studies are selected depending on whether the intervention under investigation is available in the NHS and can be practically and safely undertaken in primary care.
• Organizational and Financial Impact Analysis
• Studies are selected and evaluated on whether the intervention under investigations may have an impact on local clinical service provision or national impact on cost for the NHS. The principles of clinical budget impact analysis are adhered to, evaluated and recorded by the author. The following factors are considered when making this assessment and analysis.
  • Eligible population
  • Current interventions
  • Likely uptake of new intervention or recommendation
  • Cost of the current or new intervention mix
  • Impact on other costs
  • Condition-related costs
  • In-direct costs and service impacts
  • Time dependencies
• Cost-effectiveness or cost-benefit analysis studies are identified where available. 

We also evaluate and include evidence from NICE accredited sources which provide economic evaluations of recommendations, such as NICE guidelines. When a recommended action may not be possible because of resource constraints, this is explicitly indicated to healthcare professionals by the wording of the CKS recommendation.

Declarations of interest

Our policy

Clarity Informatics requests that all those involved in the writing and reviewing of topics, and those involved in the external review process to declare any competing interests. Signed copies are securely held by Clarity Informatics and are available on request with the permission of the individual. A copy of the declaration of interest form which participants are asked to complete annually is also available on request. A brief outline of the declarations of interest policy is described here and full details of the policy is available on the Clarity Informatics website. Declarations of interests of the authors are not routinely published, however competing interests of all those involved in the topic update or development are listed below. Competing interests include:

• Personal financial interests
• Personal family interest
• Personal non-financial interest
• Non-personal financial gain or benefit

Although particular attention is given to interests that could result in financial gains or losses for the individual, competing interests may also arise from academic competition or for political, personal, religious, and reputational reasons. An individual is not obliged to seek out knowledge of work done for, or on behalf of, the healthcare industry within the departments for which they are responsible if they would not normally expect to be informed.

Who should declare competing interests?

Any individual (or organization) involved in developing, reviewing, or commenting on clinical content, particularly the recommendations should declare competing interests. This includes the authoring team members, expert advisers, external reviewers of draft topics, individuals providing feedback on published topics, and Editorial Steering Group members. Declarations of interest are completed annually for authoring team and editorial steering group members, and are completed at the start of the topic update and development process for external stakeholders.

Competing interests declared for this topic:

None.