Table 2.

Strength of evidence ratings for hypothesised explanations for the rise in detentions

Explanatory factor	Evidence for temporal relationship with change in detention ratesa	Evidence for, or self-evident plausibility of, causal relationship to risk of detentiona	Ratingb
(1) Social and economic hardship	Equivocal	Equivocal	1
(2) Increased drug and alcohol use	Equivocal	Equivocal	1
(3) Demographic change (increased numbers of those at risk of detention)	Supported	Equivocal	2
(4) Increasing rates of mental illness	Supported	Equivocal	2
(5) Reduced informal social support	Equivocal	Supported	1
(6) Reduced availability and quality of community mental health services	Equivocal	Supported	2
(7) Reduced availability of alternatives to admission	Contradicted	Equivocal	0
(8) Reduced quality and/or responsiveness of crisis services	Equivocal	Contradicted	0
(9) Reduced in-patient bed capacity	Supported	Equivocal	1
(10) Less continuity of care at MHA assessments	Equivocal	Equivocal	1
(11) Greater aversion to risk among mental health professionals	Equivocal	Supported	1
(12) Changes in prescribing practice	Contradicted	Equivocal	0
(13) Changes in legal and clinical practice in respect of capacity	Supported	Supported	2
(14) Introduction of CTOs (and earlier discharge)	Supported	Contradicted	0
(15) Police more likely to bring people to a health-based place of safety	Supported	Equivocal	2
(16) Better data reporting in recent years	Equivocal	Supported	1
(17) Increase in transfers between hospitals during admission leads to double-counting	Equivocal	Supported	1

MHA, Mental Health Act 1983; CTO, community treatment order.

^a.Contradicted, contradicted by current evidence; equivocal, absent or ambiguous evidence; supported, supported by current evidence.

^b.0, hypothesis is contradicted by available evidence; 1, lack of evidence or available evidence is ambiguous or mixed; 2, hypothesis is supported by the balance of available evidence.