Self-reported knowledge of national guidelines for clinical screening for hip dysplasia: a web-based survey of midwives and GPs in Denmark

Summary

This study demonstrates that self-reported recognition of written statements of nationally recommended clinical hip examinations in the screening of DDH among GPs, midwives, and GPs in training was low (<60%) overall for two out of three correct statements of recommended examinations. Further, over 50% of responders were unable to identify two out of three statements as being false.

Strengths and limitations

Responses were collected using an online anonymised survey as a low-cost and easily accessible tool, with the added benefit of increasing the reach of the questionnaire, as it was expanded from email invitations to include invitations via closed social media groups for health professionals. A drawback of these choices was the inability to estimate response rates for the survey invitation as the number of active users in the groups was unknown. The medical specialty of the physicians in the physician group was also unknown. As a consequence, the internal and external validity of the sample population is difficult to assess.

The identity of each participant could not be confirmed as recruitment was not made directly via personal email for all responders. The social media group for physicians used to advertise the study implements an identity check to verify that members hold a Danish medical authorisation and is a tightly moderated forum. In the social media group for midwives used to advertise the study, an administrator makes an assessment of a user’s profile before entering a new member. However, these validations do not ensure only midwives can be accepted for inclusion in the social media group and the GP specialty of the included physicians cannot be confirmed. Further, IP tracking and cookie checks were not used and, therefore, double entries were not monitored. Responders were instructed to rely on their own knowledge and not seek outside help, but no checks were made to ensure their adherence to these instructions. As midwives make up 55% of the sample, but only 34% of the background population of screeners, the study population is not an accurate representation of the background population, which should be considered when interpreting the overall correct answer percentages of this study.

Despite these limitations, participants were expected to have adhered to the instructions provided in the questionnaire, thus making their answers valid.

Comparison with existing literature

Screening for DDH in Denmark is described in the national recommendations for neonatal DDH screening. The guidelines recommend that the neonate clinical hip examination should include the Barlow and Ortolani manoeuvres, the Galeazzi test, and a test for limited hip abduction. However, it is the authors’ experience that, in reality, generally only the Ortolani manoeuvre is performed in the clinical screening by midwives and GPs. If the national recommendations are not reflected in daily clinical practice, this could explain the high overall correct answer rate for the description of the Ortolani manoeuvre, but also the low correct answer rates for the Galeazzi and hip abduction tests.

These findings present a challenge, as clinical screeners are generally able to recognise the examination they have been taught and are using in clinical practice, but are unable to recognise recommended examinations that are, in the authors' experience, rarely used outside orthopaedic consultations. The Barlow and Ortolani manoeuvres have high negative predictive values but low positive predictive values¹¹ when used exclusively; when combining these manoeuvres the sensitivity and specificity increases to 74%–99% and 98%–99%, respectively, with variation depending on the examiner’s skill level.¹² Reliance on a single clinical hip examination is, therefore, inadvisable as it decreases the predictive value of the screening.

The positive predictive value of clinical screening in referrals in the UK, where a screening programme for DDH similar to the Danish screening is implemented, is low, and has been steadily declining over the past 20 years. It has declined from a positive predictive value of clinical examinations of referrers at 28% in 1997 to 4% in 2015. This has been attributed to an expansion and fragmentation of the pool of screeners.^7,13 Düppe and Danielsson found a correlation between delegating clinical hip examinations to screeners not involved in the treatment or specialised diagnostics of DDH and an increase in referral and treatment rates without lowering the rate of late diagnosis of DDH in newborns.¹

There exists no formalised training in DDH screening for midwives and GPs in Denmark, even though all Danish midwives and GPs take part in the primary clinical screening, and it has been established that clinical hip examinations are difficult to perform and interpret correctly, even for hip specialists.¹⁴

The aforementioned British and Swedish studies^1,7,13 conclude that including professions not specialised in paediatric hip diseases lowers the efficacy of a DDH screening programme. The present survey suggests that a possible explanation could be that the training of clinical screeners may be inadequate in giving screeners the necessary knowledge of which hip examinations to perform, which lowers their chances of a true positive examination result.

Further, the Danish screening for DDH is not centralised to examiners with specialist training in hip examination and treatment. Similar to the programme in the UK, it is performed by generalist health professionals. The number of screeners, combined with the reported yearly DDH screenings from responders in this study, means that with an underlying incidence rate of DDH of 0.7%–1%,^1,2 an examiner in the Danish screening programme for DDH will rarely experience a positive hip examination. Additionally, if a screener detects a positive result, contrary to hip specialists, an immediate follow-up ultrasound examination is not available and validation of a positive clinical result is, therefore, not possible.

Implications for practice

These findings provide a possible partial explanation for the observed low predictive value of clinical hip examinations performed by primary DDH screeners. They suggest a need for efforts to be made to revise the training of DDH screeners in Denmark in order to increase their level of knowledge.

The recognition of written descriptions of two out of three recommended clinical hip examinations in the Danish screening programme for DDH is overall low among current screeners. Screeners need further education in order to increase the efficacy of clinical screening for DDH.