Table 1.
The relationship of potential explanatory factors to detention rates: exploration of available national data
| Hypothesis number | Potential explanatory variable (measure) | Data source | Data points,years | Mean annual increase,variable units | Mean annual change,standardised units | Relationship to detention rate,coefficient (95% CI), P | Significant association corroborates hypothesis? |
|---|---|---|---|---|---|---|---|
| 1 | Relative poverty UK (% people earning <50% median national income) | OECD14 | 20 | −0.10 | −0.12 | 0.36 (−1.55 to 2.26), 0.695 | Not significant |
| 1 | Income inequality (Gini coefficient) | ONS15 | 28 | −0.05 | −0.04 | −0.38 (−1.88 to 1.12), 0.605 | Not significant |
| 1 | Rate of evictions per 100 000 population | Mortgage and landlord possession statistics16 | 18 | −3.44 | −0.12 | 0.02 (−0.04 to 0.08), 0.512 | Not significant |
| 1 | Unemployment rate (over 16 years old and seasonally adjusted) | Labour force survey17 | 29 | −0.10 | −0.06 | −1.56 (−3.74 to 0.62), 0.153 | Not significant |
| 1 | Number of racial hate crimes recorded by the police per 1000 population | GOV.UK hate crime statistics18 | 6 | 0.08 | 0.42 | n.a. | |
| 1 | Number of reported racist incidents per 1000 population (England and Wales) | 4 | −0.04 | −0.53 | n.a. | ||
| 1 | Proportion of people in England and Wales reporting experience of racial prejudice | British social attitudes survey19 | 20 | −0.24 | −0.06 | 0.13 (−0.07 to 0.33), 0.192 | Not significant |
| 1 | Fear and exclusion of people with mental illness, 1994–2014 | Time to Change Attitudes to Mental Illness Research Report (2014)20 | 14 | −0.23 | −0.08 | −1.38 (−2.70 to −0.07), 0.04 | No |
| 1 | Understanding and tolerance of mental illness, 1994–2014 | 14 | −0.01 | −0.01 | −0.47 (−2.30 to 1.35), 0.58 | Not significant | |
| 1 | Integrating people with mental illness into the community, 1994–2014a | 14 | 0.21 | 0.08 | 0.06 (−1.50 to 1.61), 0.94 | Not significant | |
| 1 | Causes of mental illness and the need for special services, 1994– 2014 | 14 | −0.05 | −0.028 | −0.37 (−1.95 to 1.20), 0.62 | Not significant | |
| 2 | Any drug use (proportion of population) | Crime survey for England and Wales21 | 22 | −0.12 | −0.08 | 0.02 (−2.77 to 2.81), 0.99 | Not significant |
| 2 | Alcohol use in general population (proportion using alcohol in past week) | ONS22 | 13 | −0.55 | −0.21 | −0.81 (−2.56 to 0.96), 0.335 | Not significant |
| 2 | Rate of cannabis use per 100 000 hospital admissions | NHS Digital hospital-admitted patient care activity23 | 19 | 0.08 | 0.13 | 9.43 (4.29 to 14.56), 0.001 | Yes |
| 2 | Rate of substance use excluding alcohol (ICD-10 F11– F19) per 100 000 hospital admissions | 19 | −0.08 | −0.03 | 0.26 (−0.26 to 0.90), 0.256 | Not significant | |
| 2 | Rate of alcohol use per 100 000 hospital admissions | 19 | 2.41 | 0.11 | −0.02 (−0.11 to 0.07), 0.632 | Not significant | |
| 3 | Proportion of males in population | ONS17,24 | 28 | 0.02 | 0.11 | 54.48 (28.44 to 80.52) <0.01 | Yes |
| 3 | Proportion of working-age adults in population | 28 | −0.13 | −0.10 | −0.66 (−8.31 to 6.99), 0.861 | Not significant | |
| 3 | Urbanicity (UK) | World Bank25 | 29 | 0.17 | 0.10 | 9 (4.60 to 13.39), <0.01 | Yes |
| 3 | Proportion of population from BAME groups | ONS17,24 | 28 | 0.30 | 0.10 | 4.86 (2.28 to 7.45), <0.01 | Yes |
| 3 | Proportion of the population not born in the UK | 28 | 0.27 | 0.11 | 5.13 (2.60 to 7.65), <0.01 | Yes | |
| 4 | Rate of all consultation episodes involving psychosis diagnoses per 100 000 population | NHS Digital hospital admitted patient care activity23 | 19 | −0.73 | −0.12 | 0.02 (−0.12 to 0.17), 0.738 | Not significant |
| 4 | % of people reporting symptoms of severe common mental disorder in the past week | APMS26 | 4 | 0.10 | 0.11 | n.a. | |
| 4 | Number of people per 1000 population assessed as having a psychotic disorder | 4 | 0.14 | 0.09 | n.a. | ||
| 5 | Social support (Congdon social fragmentation index median) | National census data27 | 3 | −0.01 | −0.09 | n.a. | |
| 6 | Number of people in contact with secondary mental health services per 1000 population | NHS Digital Mental Health Bulletin28 | 14 | 1.80 | 0.26 | 1.2 (−0.11 to 2.51), 0.068 | Not significant |
| 6 | Mental health spend (inflation adjusted) per capita (£)a | NHS reference costs29 | 13 | 2.21 | 0.19 | −0.07 (−0.16 to 0.03), 0.162 | Not significant |
| 6 | Mental health spend per person in contact with secondary mental health services (£) | 13 | −50.90 | −0.10 | −0.01 (−0.02 to 0.00) | Yes | |
| 6 | Mental health nurses number per 100 000 population | NHS Digital Mental Health Bulletin28 | 9 | −1.57 | −0.30 | n.a. | |
| 6 | Nurses in community psychiatry number per 100 000 population | 9 | 0.08 | 0.10 | n.a. | ||
| 6 | Nursing support staff total number per 100 000 population | 9 | −0.37 | −0.28 | n.a. | ||
| 6 | Nursing support staff in community psychiatry per 100 000 population | 9 | −0.09 | −0.25 | n.a. | ||
| 6 | Number of psychiatrists per 100 000 population | 9 | −0.16 | −0.35 | n.a. | ||
| 6 | Number of CMHT patient contacts per 1000 population | 6 | 2.55 | 0.22 | n.a. | ||
| 6 | Number of CMHT contacts per person in contact with mental health services | 6 | −0.09 | −0.20 | n.a. | ||
| 7,8 | Number of CRT contacts per 1000 population | 6 | 2.24 | 0.33 | n.a. | ||
| 7,8 | Number of CRT contacts per person in contact with secondary mental health services | 6 | −0.00 | −0.01 | n.a. | ||
| 9 | NHS psychiatric beds per 100 000 population | NHS Digital Mental Health Bulletin: bed availability and occupancy data30 | 28 | −3.24 | −0.12 | −0.55 (−0.75 to −0.3), <0.01 | Yes |
| 9 | Detentions in non-NHS hospitals per 100 000 population | NHS Digital MHA statistics – annual figures11 | 28 | 0.44 | 0.13 | 3.6 (2.43 to 4.78), <0.01 | Yes |
| 12 | Percentage of all detentions in non-NHS hospitals | 28 | 0.37 | 0.12 | 3.7 (2.23 to 5.17), <0.01 | Yes | |
| 12 | Antipsychotic depot prescriptions (in 1000s) | NHS Digital prescription cost analysis31 | 16 | −4.00 | −0.25 | 0.17 (−0.06 to 0.40), 0.137 | Not significant |
| 12 | Clozapine prescriptions (in 1000s) | 16 | 0.08 | 0.06 | 1.41 (−0.80 to 3.62), 0.188 | Not significant | |
| 14 | Readmissions to hospital following revocations of CTO per 100 000 population | NHS Digital MHA statistics – annual figures11 | 8 | 0.32 | 0.35 | n.a. | |
| 15 | All place of safety orders per 100 000 population | 28 | 1.43 | 0.12 | 1.01 (0.61 to 1.42), <0.01 | Yes | |
| 15 | Number of conversions from s.135 or s.136 to s.2 | 28 | 0.21 | 0.13 | 6.74 (4.22 to 9.26), <0.01 | Yes | |
| 15 | Number of conversions from s.135 or s.136 to s.3 | 28 | 0.02 | 0.09 | 8.2 (−5.68 to 22.09), 0.235 | Not significant |
OECD, Organisation for Economic Co-operation and Development; ONS, Office for National Statistics; n.a., not applicable; BAME, Black, Asian and minority ethnic; APMS, Adult Psychiatric Morbidity Survey; NHS, National Health Service; CMHT, community mental health team; CRT, crisis resolution team; MHA, Mental Health Act 1983; CTO, community treatment order; s., section (of MHA).
a.
Linear regression was conducted for this variable, not Prais–Winsten regression, as there was no evidence of auto-correlations.