Suicide rate has fallen in Catalans with HIV – but is still higher than in the general population

A study presented at the recent 19th European AIDS Conference (EACS 2023) in Warsaw found that the suicide rate in people living with HIV in Catalonia and the Balearic Islands fell between 1998 and 2020.

But the rate is still more than twice the rate in the general Spanish population and, because deaths due to HIV and co-infections have fallen during the same period, it still causes a significant proportion of all deaths in the HIV-positive population.

The suicide rate both absolutely and relative to others was especially high in women, in older people, in recently diagnosed people and in people with low CD4 counts. It was not significantly related to any physical or mental co-morbidity other than depression. People who had not received antiretroviral therapy (ART) for more than a year were also much more likely to commit suicide, but this should probably be seen as a symptom of suicidality rather than a cause of it.

The study looked at PISICS, a cohort of people with HIV attending 11 hospitals in Catalonia and the Balearic Islands in Spain. It is a prospective cohort, with the number enrolled increasing over time. In total, 30,394 people have joined it, but 4102 people have died and 12,693 have been lost to follow-up.

As time has gone on, more cohort members have died, but because the cohort has been expanding, the mortality rate – the percentage of members who died in each five-year period – has gone down. So from 1998-2003, there was a mortality rate of 12% over five years. But from 2015-2020 it had halved to 6% over five years.

Among the deaths, there were 76 suicides – 1.85% of deaths. Although this is a small proportion of the total, neither the absolute number of deaths due to suicide nor the proportion that were suicides decreased over time. From 1998-2003 there were nine suicides – 1.05% of all deaths. By 2009-2014 there were 34 suicides (2.65% of deaths), which reduced to 21 suicides (1.7% of deaths) from 2015-2020.

However, this does not take account of the overall expansion of the cohort, or of the amount of person-years contributed by each cohort member. So the researchers computed a 'Crude Mortality Rate'. This divides the number of people in each five-year period who committed suicide by the number of person-years they spent in the cohort. This is the truest measurement of the rate of suicide per individual over time, and it fell from 0.43 to 0.21 over time.

The reason this is important is that suicide rates are notoriously hard to estimate from raw death figures alone. Firstly, it is difficult to establish which are genuine suicides and which are unintentional deaths, such as overdoses. Secondly, it is very hard to derive the true rate of suicide from raw cause-of-death statistics without having the granularity afforded by a closely observed prospective cohort of people whose likelihood of death, as well as the causes of it, are known. This has led to some inaccurate figures being published on this most sensitive of subjects, as we explored in another article.

Find out more: The hardest outcome of all: HIV and suicide

The researchers also computed hazard ratios – the risk that any one person would commit suicide – by comparing the suicide rate in particular groups with the total number of person-years for people still alive in the cohort (subtracting deaths due to other causes and periods lost to follow-up, this came to 13,689 person-years).

Suicide was more common in older people: those over 50 had six times the suicide rate of people aged 16-29, and people in their forties nearly four times the rate. But conversely, the recently diagnosed were much more vulnerable to suicidality than people who had lived with HIV longer: the suicide rate in people who had been diagnosed for less than five years was no less than 34 times greater than in people diagnosed ten or more years ago.

Having a low CD4 count was also connected to suicidality; people with a count below 200 had three times the suicide rate of people with higher counts. As said above, people who had been off ART for more than 12 months had 37.5 times the suicide rate of people on ART, but whether this is a cause of suicidality or a symptom of it, and should be regarded as an alarm signal, is debatable.

Notably, no specific co-morbidity was significantly associated with suicide other than depression, which doubled the risk of suicide. Suicide was less common in people with cancer or liver disease, but this may just indicate a higher risk of death due to the co-morbidity than to suicide.

The statistic people may really want to know, however, is whether people with HIV are more likely to kill themselves than the general population without HIV.

The suicide rate in the general population in Spain is a relatively high 8.4 per 100,000 per year - which over a five-year period would translate to 0.042% or one in 2381 Spaniards.

The suicide rate in the cohort was and remained higher than this, though not by an order of magnitude, as some other studies have reported, and has fallen over time. The Standardised Mortality Ratio (SMR) is the incidence of death due to the cause of interest (in this case, suicide) in a study population divided by the rate in the general population.

In 1998 the SMR in the cohort as a whole was 5.45, meaning that people with HIV at this time killed themselves at more than five times the rate of other Spaniards. By 2015-2020 it had more than halved to 2.26. In men it fell by 60% from 2.4 to 1.4.

In women, the reported SMR for 1998-2004 was 23 – implying that women with HIV were 23 times more likely to commit suicide than women in general – but this is probably a chance finding. There were few women in the cohort and a total of nine suicides in this time period, so the confidence interval is very wide and it’s probably better to ignore this figure.

In the other three five-year periods, the SMR for suicide in women with HIV was about the same for each period, at 6.57, 7.76 and 5.37. This shows not only that the risk of suicide in women has not fallen, but that it has remained both somewhat higher in women than in men in the cohort, and considerably higher in women with HIV than in women without it. On the other hand, the suicide rates in men and in the predominantly male cohort agree roughly with the rate observed in a UK study from 2017.

This also shows that people recently diagnosed with HIV continue to react to an HIV diagnosis as a huge shock – from which some are unable to recover.

If you've been affected by some of the issues in this article, Samaritans can be contacted in the UK on 116 123, and in the US, the National Suicide Prevention Lifeline is 1-800-273-8255. Other international helplines can be found at www.befrienders.org or via this Wikipedia page.