The concept of severe mental disorder (SMD) arises, in the field of community mental health care. It tries to transcend the limited perspective of clinical diagnosis as the basis for organizing health care. This term includes all long-term mental disorders that lead to the presence of disability and social dysfunction as a consequence of the symptoms of the disease ¹. Mental health care is prioritized in the five SIDDD dimensions: Safety towards oneself and others; social and family support; diagnosis referred to psychotic disorders (excluding organic) and some personality disorders; duration of disease and treatment (considering a time greater than two years); presence of disability (referring to a moderate to severe impairment of work, social and family functioning) ².

In Colombia, about 40.1% of the adult population has had at least one mental disorder, and about 15.2% of patients have been hospitalized for an acute event of SMD ³. In response to this situation, the Colombian Ministry of Health has established public health policies aimed at the prevention and care of the mental health of the population, as an integrated model within the framework of primary health care: among them is the Ten-Year Public Health Plan 2012-2021; that prioritizes social coexistence and mental health with the aim of reducing the impact of the global burden of disease, which is estimated for mental illnesses in 33% of the years lived with disability ^4-6.

The complexity of managing SMD and the deficiency in the coverage of specialized services is compounded by the economic impact derived from the treatment ⁷. In the United States, it reached 148 billion dollars annually, while indirect costs in developed countries are up to six times higher compared to those reported in developing countries ⁸. To reduce the impact derived from care in mental health events, the Colombian Health Quality Management Guarantee System recommended that health institutions optimize care resources, evaluate and improve the quality of care in the population requiring hospitalization ^9,10.

One of the main indicators of the quality of care in psychiatric patients is the early rehospitalization known as "revolving door patients", defined as the reinstitutionalization of a patient, for the same clinical condition, in the following three months after discharge hospitable. Readmission in chronic psychiatric patients can reach 66% ^11-13. It is estimated that at least 50% of patients who are regular users of inpatient psychiatric services have been re-hospitalized during the first year after hospital discharge. Among the main determinants of early re-hospitalization, those related to the onset and course of the disease, the characteristics of the psychopathological picture, treatment, social support and life experiences are reported ^14,15.

Despite the recommendation of the Ministry of Health for specialized mental health institutions to evaluate the quality of health care, it is therefore important to know the frequency and determinants of mental health re-hospitalization. The objective of this research was to determine the frequency and the determinants of hospital readmission in patients with a diagnosis compatible with SMD treated at an IPS specialized in mental health in Santiago de Cali.

An analytical observational study of cases and controls was carried out, with retrospective data collection, in patients with a diagnosis compatible with severe mental disorder discharged from a specialized Health Provider Institution in Cali, Colombia. A review of the IPS information system database of records dated between January 1 and December 31, 2017 was carried out. All records of adult patients of both sexes, with SMD, classified according to the ICD-10 codes, who were hospitalized with a diagnosis of severe mental illness, were included. A case was defined as any registry of patients who were re-hospitalized for a period of less than three months for the same cause of a previous hospitalization in a period of three months after discharge, and as a control, any registry of patients who during the following three months after discharge, he was not re-hospitalized for the same cause.

Sample size and sampling Information from all patient records that met the selection criteria, 105 cases and 315 controls, was analyzed for a sample size of 420 records. As all re-hospitalized patients were included, the sampling strategy in the cases was not specified. With respect to the controls, a simple random sampling was carried out to select them (Figure 1).

Figure 1

To determine the power of the number of records included in the study, the size and power of the sample was verified through the Openepi statistical package available at https: //www.openepi. com / SampleSize / SSCC.htm, taking into account a reliability of 95%, a power of 80%, taking three controls for each case, with a hypothetical proportion of exposure in the controls of 40% for the variable readmission and in the cases of 60%, and an OR of 2, for a suggested sample size of 88 cases and 264 controls.

Of the 1,087 hospital admissions reported, 249 repeated records were discarded and 99 that only had one day of admission; therefore, they did not correspond to hospitalizations, thus leaving a total of 739 records, of which 636 corresponded to hospitalizations by SMD in patients over 18 years of age, from these, all the records that met the criteria to be classified as cases were selected in total 105. Of the 531 records that met the criteria to be classified as controls, 315 records were randomly selected. Of the total population hospitalized at the institution during the study period, 14.2% had at least one readmission and only two patients were readmitted on four occasions during the three months following discharge for the same cause.

Readmissions during the study period occurred from the beginning of the year. In all the months there was at least one case for each diagnosis, on average 12.7 cases; January being the month with the lowest number with 3 (2.0%) cases and the months of July, September and October with the highest number on average 16 cases (11.1%), regarding admission diagnoses: 33 (31.4) of the patients were readmitted for Dx of schizophrenia, 29 (27.6) for depressive disorder and 43 (41.0%) for bipolar affective disorder (Figure 2).

Figure 2

With respect to demographic characteristics, age presented a median for cases of 37 and for controls of 47; 50% of the study population was over 44 years old, 58% belonged to the female sex; single marital status was the most frequent in 31% of patients; For schooling in a higher proportion, 52% had secondary schooling, in occupation 60% were active at work; with regard to residence, the urban area predominated with 90%; in economic dependence, 50% depended economically on their relatives and 86% reported having support from a caregiver (Table 1).

Table 1

		Summary
Characteristic	Description	n	%
Age (years)	18-44	210	50.0
	≤45	210	50.0
Gender	Man	183	43.5
	Woman	237	56.4
Marital status	Single	130	30.9
	Married	123	29.2
	Separated	95	22.6
	Living with partner	60	14.2
	Widow	12	2.8
	None	7	1.6
	Secondary	220	52.3
	Technical	64	15.2
	University	27	6.4
Occupation	Works	254	60.4
	Does not work	166	39.5
Type of home	Urban	381	90.7
	Rural	9	9.2
Economically dependent	Yes	214	50.9
	No	206	49.0
On whom is the economic dependence	Family	209	49.7
	Own resources	206	49.0
	Other people	5	1.1
Carer present	Yes	364	86.6
	No	56	13.3
Relationship to carer	Wife/husband	131	36.0
	Father	104	28.5
	Child	71	19.5
	Brother/sister	46	4.6
	Other family	9	3.2
Schizophrenia diagnosis	Yes	314	25.2
	No	106	74.7
Diagnosis of depressive disorder	Yes	180	42.8
	No	240	57.1
Diagnosis of bipolar affective disorder	Yes	286	68.1
	No	134	31.9
Presence of comorbidities	Yes	162	38.5
	No	258	61.4
SPA consumption	Yes	79	18.8
	No	341	81.1
Number of readmissions	1	66	62.8
	2	34	32.3
	3	3	2.8
	4	2	1.9
Treatment adherence	Yes	296	70.4
	No	124	29.5
Opportune delivery of medication	Yes	383	8.8
	No	37	91.1

Regarding the clinical characteristics, the diagnoses were distributed as follows; 25% were admitted for schizophrenia, 42% for depressive disorder, and 31% for bipolar affective disorder; with respect to the presence of comorbidities, 61% did not suffer from them; Regarding the consumption of psychoactive substances, it was found more frequently that 81% did not consume them; regarding the follow-up after hospitalization, 95% if they had it; Regarding adherence to treatment after discharge, 70% were adherents; for the timely delivery of the medication, 91% were delivered in a timely manner; Regarding the total number of readmissions during the study period, it was found that 62% had 1 readmission, 30% had 2 readmissions, 3% had 3 readmissions and 3% had 4 readmissions (Table 1).

It was found that none of the socioeconomic variables presented an association. Of the clinical variables, four were found: diagnosis of depressive disorder was found to protect against readmission (OR: 0.41) and for the diagnosis of bipolar affective disorder a higher risk of readmission was found (OR: 1.8). Regarding the consumption of SPA, an OR of 2.0 was obtained, finding that patients with this condition are more likely to be readmitted; and finally, for pharmacological adherence, an OR of 0.28 was obtained, being a protective factor to avoid readmission (Table 2).

Table 2

Characteristic	Description	n	Cases	Controls	OR	CI (95%)	p-value
Gender	Masculine	183	44	139	1.0	0.68-1.75	0.69
	Femenine	237	61	176
Schooling	Yes	413	104	309	2.0	0.24-93.75	0.50
	No	7	1	6
Marital status	Has partner	183	40	143	0.7	0.45-1.18	0.19
	No	206	45	161
Economically dependent	Yes	214	60	154	1.3	0.87-2.23	0.14
Occupation	Works	254	65	189	1.0	0.67-1.75	0.72
	Does not work	166	40	126
Presence of carer	Yes	364	92	272	1.1	0.55-2.37	0.74
	No	56	13	43
Schizophrenia	Yes	105	32	73	1.4	0.85-2.43	0.13
	No	315	73	242
Depressive disorder	Yes	180	29	151	0.4	0.24-0.68	0.003
	No	240	76	164
Bipolar affective disorder	Yes	135	44	91	1.8	1.09-2.87	0.01
	No	285	61	224
Comorbidities	Yes	162	38	124	0.8	0.53-1.41	0.56
	No	258	67	191
SPA consumption	Yes	79	29	50	2.0	1.148-3.51	0.00
	No	341	76	265
Walk-in controls	Yes	402	104	298	5.9	0.90-250.24	0.05
	No	18	1	17
Adherence to drug treatment	Yes	296	52	244	0.2	0.17-0.46	0.00
	No	124	53	71
Opportune delivery of medication	Yes	383	91	292	0.5	0.24-1.12	0.05

The multivariate logistic regression analysis, in which the dependent variable was hospital readmission; No statistically significant association was observed with the following variables: bipolar affective disorder, depressive disorder and SPA use (Table 3).

Table 3

Characteristic	Description	n	Cases (n)	Controls (n)	OR	CI (95%)	p	Adjusted OR	CI (95%)	p
Bipolar affective disorder	Yes	135	44	91	0.4	0.24-0.685	0.00	0.9	0.53-1.67	0.83
	No	285	61	224
Depressive disorder	Yes	180	29	151	0.4	0.24-0.685	0.00	0.5	0.31-1.03	0.06
	No	240	76	164
SPA consumption	Yes	79	29	50	2.0	1.14- 3.51	0.00	1.5	0.86-2.63	0.14
	No	341	76	265
Treatment adherence	Yes	296	52	244	0.2	0.17-0.467	0.00	0.3	0.21-0.58	0.00

The final model yielded as an independent and statistically significant variable, adherence to treatment as a protective factor to prevent hospital readmission in patients with SMD with an adjusted OR of 0.35.

The present investigation evaluated the frequency and determinants of hospital readmission in patients diagnosed with the mental health disorder in a specialized mental health center in the city of Cali, during the year 2017. It was found that a total of 105 patients presented at least one early readmission to the IPS during the study period, this figure corresponds to 14.2% of the total readmissions to the institution, similar to what was found in the Risaralda Mental Hospital that 320 (13.8%) patients had at least one early readmission during the years 2011 to 2013 ¹⁶; In Barcelona (Spain) they found at 30 days of discharge the percentage of readmissions was 14.7% ^11,17; In Europe, the readmission percentage was higher, readmissions for mental disorders were found in 26.5% in the study population ¹⁸. This difference may correspond to the type of population studied and characteristics studied.

In our study, bipolar affective disorder was the predominant diagnosis (41.9%) of readmissions, similar to what was found in Antioquia where 46.8% of readmissions were reported with this diagnosis ¹⁹. Regarding adherence to treatment, it was found that 70% of the patients were adherents, a finding that is related to the Antioquia study in which 72.5% of the studied population was adherent ⁽¹⁹⁾. Three of the clinical variables included in the study gave an association. Patients with depressive disorder have a lower risk of readmission, OR: 0.41, as were patients who were adherent to treatment with (OR: 0.29) at discharge (Table 3). Regarding the consumption of SPA, only 27.6% of the patients who were readmitted consumed them. When comparing our results with other studies on factors associated with the readmission of psychiatric patients, a higher percentage of psychoactive substance use is found with 80.3% of the cases having at least one readmission ¹⁶.

From the sociodemographic factors, it was possible to determine that the urban area (90.7%) predominated as the origin of the patients, this result was similar to that reported in the study carried out in Risaralda where the urban population corresponded to 95% ¹⁶, although the origin It is not related to the reports of distribution of mental pathology in our country; according to the 2015 National Survey of Mental Health, the lifetime prevalence of any mental disorder in adults reaches 10% in urban areas and 6.1% in rural areas ³. The low representation of the rural population in this study is related to the type of health regime that the institution serves since it only provides services to EAPB of the contributory regime. Regarding the association of the variables, sociodemographic and personal, with the readmission of psychiatric patients, no statistically significant association was found. Although sex did not present statistical significance, 58% of the patients who were readmitted were female, a situation that is consistent with studies carried out in the country. In a study carried out at the Nuestra Señora de la Paz Clinic, Bogotá, where most of the readmissions 59.2% corresponded to women ²⁰, while the study carried out at the Risaralda University Mental Hospital found that 60% of the readmissions belonged to the male sex ¹⁶.

People with severe mental disorder (SMD) are characterized by presenting a series of difficulties that increase their fragility in coping with the incidents of daily life and are associated with the need for continuous help in order to achieve the highest level of personal autonomy possible. Thus, many people with SMD have difficulties to independently cover their housing needs and maintain a decent and adequate home for their needs and desires ²¹. In Colombia, following Law 100, there has been a gradual process of “dehospitalization” (hospital discharge of people with mental disorders). The reduction in hospital stays has not, however, meant a paradigm shift in the care of people with mental disorders, as hospitalization are still the main axis of their care, while the alternatives for community care and rehabilitation are few ²².

It is important to mention that the data for the measurement of adherence and consumption of SPA, in this study was obtained from medical records in clinical history, and an instrument was not used for this purpose due to its retrospective nature, to which the difference in results in other studies can be attributed.

The total of patients who were readmitted contributed 153 hospitalizations (20.7%) of the total of the 739 hospitalizations presented in 2017 in the Life Cycle IPS. For this reason, it is important to follow up on this event to promptly intervene in patients who present more than one readmission to establish the causes and take actions to reduce their frequency. Hospital readmissions generate an increase in costs in health systems and increases the negative effects on family support and social support systems that patients have. Hospital readmissions are considered an indicator of quality in psychiatric care and it is also important to take them into account to measure the severity of the disease.