Which are the most useful scales for predicting repeat self-harm? A systematic review evaluating risk scales using measures of diagnostic accuracy

OBJECTIVES

The aims of this review were to calculate the diagnostic accuracy statistics of risk scales following self-harm and consider which might be the most useful scales in clinical practice.

DESIGN

Systematic review.

METHODS

We based our search terms on those used in the systematic reviews carried out for the National Institute for Health and Care Excellence self-harm guidelines (2012) and evidence update (2013), and updated the searches through to February 2015 (CINAHL, EMBASE, MEDLINE, and PsychINFO). Methodological quality was assessed and three reviewers extracted data independently. We limited our analysis to cohort studies in adults using the outcome of repeat self-harm or attempted suicide. We calculated diagnostic accuracy statistics including measures of global accuracy. Statistical pooling was not possible due to heterogeneity.

RESULTS

The eight papers included in the final analysis varied widely according to methodological quality and the content of scales employed. Overall, sensitivity of scales ranged from 6% (95% CI 5% to 6%) to 97% (CI 95% 94% to 98%). The positive predictive value (PPV) ranged from 5% (95% CI 3% to 9%) to 84% (95% CI 80% to 87%). The diagnostic OR ranged from 1.01 (95% CI 0.434 to 2.5) to 16.3 (95%CI 12.5 to 21.4). Scales with high sensitivity tended to have low PPVs.

CONCLUSIONS

It is difficult to be certain which, if any, are the most useful scales for self-harm risk assessment. No scales perform sufficiently well so as to be recommended for routine clinical use. Further robust prospective studies are warranted to evaluate risk scales following an episode of self-harm. Diagnostic accuracy statistics should be considered in relation to the specific service needs, and scales should only be used as an adjunct to assessment.

Scales for predicting risk following self-harm: an observational study in 32 hospitals in England

OBJECTIVE

To investigate the extent to which risk scales were used for the assessment of self-harm by emergency department clinicians and mental health staff, and to examine the association between the use of a risk scale and measures of service quality and repeat self-harm within 6 months.

DESIGN

Observational study.

SETTING

A stratified random sample of 32 hospitals in England.

PARTICIPANTS

6442 individuals presenting with self-harm to 32 hospital services during a 3-month period between 2010 and 2011.

OUTCOMES

21-item measure of service quality, repeat self-harm within 6 months.

RESULTS

A variety of different risk assessment tools were in use. Unvalidated locally developed proformas were the most commonly used instruments (reported in n=22 (68.8%) mental health services). Risk assessment scales were used in one-third of services, with the SAD PERSONS being the single most commonly used scale. There were no differences in service quality score between hospitals which did and did not use scales as a component of risk assessment (median service quality score (IQR): 14.5 (12.8, 16.4) vs 14.5 (11.4, 16.0), U=121.0, p=0.90), but hospitals which used scales had a lower median rate of repeat self-harm within 6 months (median repeat rate (IQR): 18.5% vs 22.7%, p=0.008, IRR (95% CI) 1.18 (1.00 to 1.37). When adjusted for differences in casemix, this association was attenuated (IRR=1.13, 95% CI (0.98 to 1.3)).

CONCLUSIONS

There is little consensus over the best instruments for risk assessment following self-harm. Further research to evaluate the impact of scales following an episode of self-harm is warranted using prospective designs. Until then, it is likely that the indiscriminant use of risk scales in clinical services will continue.

Genetic variation in DNMT3B and increased global DNA methylation is associated with suicide attempts in psychiatric patients

Recently, a significant epigenetic component in the pathology of suicide has been realized. Here we investigate candidate functional SNPs in epigenetic-regulatory genes, DNMT1 and DNMT3B, for association with suicide attempt (SA) among patients with co-existing psychiatric illness. In addition, global DNA methylation levels [5-methyl cytosine (5-mC%)] between SA and psychiatric controls were quantified using the Methylflash Methylated DNA Quantification Kit. DNA was obtained from blood of 79 suicide attempters and 80 non-attempters, assessed for DSM-IV Axis I disorders. Functional SNPs were selected for each gene (DNMT1; n = 7, DNMT3B; n = 10), and genotyped. A SNP (rs2424932) residing in the 3' UTR of the DNMT3B gene was associated with SA compared with a non-attempter control group (P = 0.001; Chi-squared test, Bonferroni adjusted P value = 0.02). Moreover, haplotype analysis identified a DNMT3B haplotype which differed between cases and controls, however this association did not hold after Bonferroni correction (P = 0.01, Bonferroni adjusted P value = 0.56). Global methylation analysis showed that psychiatric patients with a history of SA had significantly higher levels of global DNA methylation compared with controls (P = 0.018, Student's t-test). In conclusion, this is the first report investigating polymorphisms in DNMT genes and global DNA methylation quantification in SA risk. Preliminary findings suggest that allelic variability in DNMT3B may be relevant to the underlying diathesis for suicidal acts and our findings support the hypothesis that aberrant DNA methylation profiles may contribute to the biology of suicidal acts. Thus, analysis of global DNA hypermethylation in blood may represent a biomarker for increased SA risk in psychiatric patients.

Sleep hygiene use in a psychiatry outpatient setting

Non-pharmacological measures are recommended prior to use of hypnotics in the latest NICE guidance. This study investigated if non-pharmacological measures are utilised prior to hypnotic prescribing in a general adult psychiatry outpatient setting, and further reviewed patient's sleep quality following implementation of sleep hygiene education. Interviews were conducted with 85 patients, and poor adherence with NICE guidance was found among the 74 (87%) patients previously prescribed a hypnotic. Just five (6.8%) patients recalled use of non-pharmacological measures prior to hypnotic prescription, 47 (63.5%) indicated non-pharmacological measures had not been discussed, while a further 22 (29.7%) could not remember. Improvement in Pittsburgh Sleep Quality Index scores following implementation of sleep hygiene education was also noted (P = 0.03). These findings suggest that increased awareness of sleep hygiene education for clinicians may be beneficial.

Measurement of lingual and palatine somatosensory evoked potentials

OBJECTIVE

A technique is presented for generating and recording lingual and palatine nerve somatosensory evoked potentials (SEPs).

METHODS

Pairs of thin, stainless steel disk electrodes were mounted onto mandibular or maxillary acrylic splints, similar to orthodontic retainers. Mandibular splint electrodes were oriented to contact the under surface of the tongue along the course of the right and left lingual nerves and maxillary splint electrodes were oriented to contact the hard palate bilaterally along the course of the palatine nerves. SEP recording electrodes were placed on the scalp 1 cm posterior to C5 and C6 (C5' and C6', respectively) using the combinatorial nomenclature of the International 10-20 system. Two reference electrode locations, Fz and C5' or C6', over the cortical hemisphere opposite that of the recording electrode, were used.

RESULTS

Right and left lingual and palatine nerve SEPs were recorded from five normal adults. SEP latencies were similar to the N13 and P18 cortical peak latencies recorded in previous studies of trigeminal nerve branches to the lips regardless of reference electrode position.

CONCLUSIONS

A more precise method of stimulating the intraoral lingual and palatine nerves was accomplished using dental splints. SEPs were easier to obtain using a contralateral cortex reference electrode location.

Electrocerebral inactivity associated with obstructive sleep apnea

We report a child who demonstrates near electrocerebral silence secondary to obstructive apnea during polysomnography. The mechanism of this suppression of cortical activity appears to be related to hypoxemia in the absence of a malignant arrhythmia.