Table 3.
Effect of number of stressful life events after onset of psychosis on number and length of subsequent relapses as indexed by hospital admission
|
Number of relapses (n=253) |
Number of relapses (with medication adherence; n=240) |
Length of relapses (n=253) |
Length of relapses (with medication adherence; n=240) |
||||||
|---|---|---|---|---|---|---|---|---|---|
| IRR (95% CI) | p value | IRR (95% CI) | p value | IRR (95% CI) | p value | IRR (95% CI) | p value | ||
| Number of stressful life events before first relapse | 1·26 (1·02–1·53) | 0·023 | 1·24 (0·99–1·52) | 0·051 | 1·52 (1·12–2·12) | 0·0028 | 1·47 (1·10–2·00) | 0·0063 | |
| Age of onset, years* | |||||||||
| <22 | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| 22 to <25 | 0·95 (0·74–1·23) | 0·68 | 0·95 (0·73–1·24) | 0·71 | 0·91 (0·63–1·32) | 0·62 | 1·03 (0·70–1·51) | 0·88 | |
| 25 to <30 | 1·20 (0·03–55·1) | 0·92 | 0·70 (0·01–36·5) | 0·86 | 1·14 (0·00–352) | 0·96 | 0·27 (0·00–85·0) | 0·62 | |
| 30 to <39 | 0·72 (0·00–16 684) | 0·95 | 3·77 (0·00–135 145) | 0·80 | 0·76 (0·00–2 175 338) | 0·97 | 28·6 (0·00–103 185 809) | 0·63 | |
| ≥39 | 1·21 (0·00–16,684) | 0·96 | 0·26 (0·00–1090) | 0·75 | 1·44 (0·00–216 033) | 0·95 | 0·09 (0·00–15 318) | 0·67 | |
| Sex | |||||||||
| Female | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Male | 0·82 (0·56–1·22) | 0·33 | 0·72 (0·48–1·08) | 0·11 | 1·12 (0·64–1·97) | 0·66 | 1·04 (0·59–1·81) | 0·89 | |
| Ethnicity | |||||||||
| White | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Asian | 1·48 (0·56–3·48) | 0·39 | 0·91 (0·29–2·37) | 0·86 | 1·66 (0·49–5·65) | 0·38 | 1·16 (0·33–4·09) | 0·80 | |
| Black African or Caribbean | 1·88 (1·16–3·14) | 0·012 | 1·61 (0·98–2·72) | 0·068 | 2·36 (1·26–4·44) | 0·0064 | 2·13 (1·14–4·00) | 0·017 | |
| Mixed | 1·97 (0·91–4·07) | 0·073 | 1·66 (0·75–3·48) | 0·19 | 1·92 (0·64–5·99) | 0·22 | 1·66 (0·56–5·14) | 0·34 | |
| Cannabis use | |||||||||
| Former | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Never | 1·39 (0·74–2·69) | 0·31 | 1·59 (0·82–3·14) | 0·17 | 1·54 (0·67–3·59) | 0·30 | 2·12 (0·89–5·20) | 0·084 | |
| Intermittent | 1·08 (0·53–2·16) | 0·83 | 1·13 (0·54–2·33) | 0·75 | 2·16 (0·90–5·26) | 0·072 | 2·47 (1·00–6·28) | 0·040 | |
| Continued hash-type | 1·23 (0·42–3·13) | 0·68 | 1·21 (0·41–3·18) | 0·71 | 1·00 (0·24–4·39) | >0·99 | 0·94 (0·23–4·05) | 0·93 | |
| Continued regular skunk-type | 1·09 (0·49–2·41) | 0·83 | 1·04 (0·46–2·31) | 0·91 | 1·66 (0·58–4·92) | 0·31 | 1·52 (0·53–4·50) | 0·41 | |
| Continued heavy skunk-type | 1·72 (0·91–3·33) | 0·10 | 1·48 (0·74–2·99) | 0·27 | 2·14 (0·84–5·54) | 0·083 | 2·34 (0·90–6·22) | 0·058 | |
| Other drug use | |||||||||
| Non-use | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Experimental | 0·79 (0·33–1·65) | 0·55 | 0·58 (0·21–1·35) | 0·25 | 1·43 (0·54–3·91) | 0·47 | 1·34 (0·51–3·66) | 0·55 | |
| Regular | 1·83 (1·02–3·24) | 0·039 | 1·74 (0·95–3·13) | 0·066 | 2·05 (0·85–5·07) | 0·089 | 2·05 (0·86–4·98) | 0·087 | |
| Nicotine use | |||||||||
| Non-use | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Intermittent | 1·98 (0·87–4·22) | 0·087 | 2·39 (1·04–5·13) | 0·031 | 2·66 (1·01–7·28) | 0·044 | 3·69 (1·39–10·1) | 0·0077 | |
| Continued | 2·00 (1·22–3·30) | 0·0067 | 2·32 (1·37–3·96) | 0·0019 | 2·02 (1·06–3·91) | 0·029 | 2·70 (1·40–5·29) | 0·0025 | |
| Alcohol use | |||||||||
| No use | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Continued alcohol | 1·24 (0·71–2·08) | 0·43 | 1·45 (0·80–2·53) | 0·21 | 1·07 (0·50–2·32) | 0·86 | 1·23 (0·58–2·65) | 0·59 | |
| Care intensity at onset | |||||||||
| Community mental health team | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Crisis team | 1·01 (0·30–3·05) | 0·98 | 0·84 (0·24–2·64) | 0·78 | 0·83 (0·19–3·50) | 0·80 | 0·74 (0·16–3·24) | 0·69 | |
| Non-compulsory admission | 2·27 (1·14–5·06) | 0·030 | 1·97 (0·97–4·42) | 0·077 | 2·33 (0·91–6·29) | 0·064 | 2·23 (0·87–6·01) | 0·083 | |
| Compulsory admission | 2·42 (1·26–5·23) | 0·014 | 2·20 (1·13–4·83) | 0·031 | 4·24 (1·76–10·8) | 0·0007 | 4·68 (1·94–12·0) | 0·0004 | |
| Relationship status | |||||||||
| In relationship | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Not in relationship | 1·33 (0·87–2·10) | 0·20 | 1·62 (1·03–2·65) | 0·046 | 2·45 (1·32–4·61) | 0·0034 | 3·34 (1·73–6·58) | 0·0002 | |
| Psychosis diagnosis | |||||||||
| Non-affective | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Affective | 0·78 (0·44–1·29) | 0·36 | 0·97 (0·54–1·66) | 0·93 | 0·53 (0·25–1·12) | 0·077 | 0·61 (0·28–1·32) | 0·18 | |
| Medication adherence | |||||||||
| Regular compliance | .. | .. | 1 (ref) | .. | .. | .. | 1 (ref) | .. | |
| Irregular compliance | .. | .. | 1·90 (1·21–3·05) | 0·0064 | .. | .. | 1·79 (1·01–3·21) | 0·037 | |
| Poor compliance | .. | .. | 3·26 (1·83–5·82) | <0·0001 | .. | .. | 2·84 (1·31–6·37) | 0·0055 | |
IRRs included adjustment for sociodemographic factors (sex, ethnicity, and relationship status) and clinical factors (psychosis diagnosis, intensity of care at onset, and alcohol, nicotine, and other drug use; with analysis stratified by cannabis use). Where indicated, the model also adjusted for medication adherence. IRR=incidence rate ratio.
*
Age of onset was modelled as a restricted cubic spline function with knots placed at ages of onset of 22 years, 25 years, 30 years, and 39 years.