Healthcare utilization in general practice before and after psychological treatment: A follow-up data linkage study in primary care

Figures & data

Figure 1. Selection of data files for analyses and data linkage.

Table I. Study sample characteristics of linked persons and total population of psychologist and GP networks in 2009 who could be linked to a record in the population records of Statistics Netherlands.

	Linked persons^1	Total population of psychologist network^2	Total population of GP network^3
Number of patients	503	43 899	382 726
Number of primary care psychologists (practices)	150 (125)	651 (553)	–
Number of GP practices	47	–	128
Patient characteristics:
Age (1 July 2009) mean (SD), range	40.0 (14.6) 6–86	38.6* (14.6) 2–95	39.5 (22.8) 0–106
Male (%)	30.8	34.3	49.0**
Number of people in household, mean (SD), range	2.7 (1.3) 1–8	2.7 (1.3) 1–13	3.0** (1.5) 1–14
Standardized disposable household income^4
(x €1000), mean (SD)	26.1 (15.2)	25.1 (14.9)	24.1* (15.7)
Psychological treatment characteristics:
Number of sessions, mean (SD), range	7.4 (4.9) 1–31	7.0 (5.0) 1–132	n.a.
Initiative request for help (%)
GP	69.6	63.5*	n.a.
Patient	22.3	27.8
Other	8.1	8.7
Type of help (%)
Advice or consultation	5.3	8.1	n.a.
Short crisis intervention	7.4	8.1
Orientation conversation	5.5	5.0
Treatment	80.3	77.1
Other	1.5	1.8
Method of treatment (%)
Cognitive behavioural therapy	37.7	41.8**	n.a.
Client-centred therapy	15.9	10.4
Systemic therapy	5.1	7.8
Psychodynamic therapy	4.0	1.6
A combination of two or more methods	30.9	32.3
Other	6.4	6.1
Way to end treatment (%)
Regular ending	68.8	71.5	n.a.
Contact broken by patient	18.2	15.5
Patient referred	13.0	13.0
Global Assessment of Functioning score^5 (%):
100–71	20.6	22.6	n.a.
70–61	36.6	37.8
60–51	35.2	33.6
50–41	7.2	5.7
< = 40	0.4	0.3

Notes: ¹People who were registered as a regular patient with one of the 47 GP practices in 2008, 2009, and 2010 and finished their psychological treatment in 2009. ²People who finished their psychological treatment in 2009. ³People who were registered as a regular patient with one of the 128 GP practices in 2009. ⁴Disposable household income is the sum of the gross income of all household members, minus income transfers, taxes on income and capital gains, income insurance premiums, and health insurance premiums. Standardization allows the disposable income of different kinds of households to be compared with the incomes of one-person households. ⁵GAF score at start of psychological treatment. A chi-squared test was used to test for differences in % male, % marital status, and % initiative request for help and way to end treatment. A t-test was used for mean age, number of people in household, disposable household income, and number of sessions. Differences were assessed between linked persons versus total population of the psychologist network and between linked persons versus total population of the GP network. *p < 0.05; **p < 0.001.

Table II. Descriptive information on GP care six months before and six months after psychological treatment and results of longitudinal multilevel logistic and Poisson regression analyses.

	Six months before psychological treatment	Six months after psychological treatment	Odds ratio and incidence rate ratio of GP care “after” compared with “before”^1 psychological treatment
Number of patients	503	503
Number of GP practices	47	47
GP care			OR/IRR (95% CI), p-value
Patients who had any contact with GP (%)	457 (90.9)	421 (83.7)	OR = 0.52 (0.15–1.86)
Number of contacts^2, total (mean, SD, range)	6.1 (5.7) 0 – 33	4.8 (5.6) 0 – 40	IRR = 0.71 (0.64–0.78)**
Patients who had contact for (%)
Any psychological symptoms or disorders (p01–p99)	182 (36.2)	149 (29.6)	OR = 0.46 (0.16–1.38)
Anxiety symptoms/disorder (p01/p74)	44 (8.7)	34 (6.8)	OR = 0.59 (0.31–1.13)
Depressive symptoms/disorder (p03/p76)	52 (10.3)	46 (9.1)	OR = 0.77 (0.43–1.38)
Patients who had contact for any social problems (z01–z29) (%)	63 (12.5)	56 (11.1)	OR = 0.80 (0.49–1.31)
Patients who had contact for any psychological or social problems (%)	233 (46.3)	195 (38.8)	OR = 0.20 (0.07–0.58)*
Patients who had contact for other symptoms or disorders without presenting any psychological or social problems (%)	259 (51.5)	284 (56.5)	OR = 0.32 (0.05–1.89)
Patients who had one or more prescriptions (%)	351 (69.8)	357 (71.0)	OR = 1.54 (0.69–3.44)
Type of medication patients were prescribed (%)	135 (26.8)	114 (22.7)	OR = 0.31 (0.11–0.89)*
Any psychotropic prescription^3	53 (10.5)	67 (13.3)	OR = 1.70 (0.98–2.94)
Antidepressants (N06A)	78 (15.5)	38 (7.6)	OR = 0.22 (0.11–0.41)**
Anxiolytics (N05B)	42 (8.3)	34 (6.8)	OR = 0.73 (0.41–1.27)
Hypnotics and sedatives (N05C)
Number of prescriptions, mean (SD), range
Total	5.7 (7.2) 0 – 48	5.7 (7.5) 0 – 48	IRR = 0.98 (0.83–1.16)
Psychotropic	1.3 (3.5) 0 – 36	1.2 (2.9) 0 – 46	IRR = 0.57 (0.31–1.02)

Notes: ¹That is, the reference group is before psychological treatment. ²All types of contact with general practice are included: consultations, home visits, telephone consultations, repeat prescriptions, contacts with practice nurses. ³Antidepressants (N06A), anxiolytics (N05B), antipsychotics (N05A), hypnotics and sedatives (N05C), psychostimulants (N06B) or psycholeptics, and psycho-analeptics in combination (N06C). For recording health problems, GPs use the ICPC classification system (International Classification or Primary Care) which has 17 sections based on different body systems/problem areas. Each section has codes that refer to symptoms (00 to 29) and codes that refer to diagnoses or diseases (70 to 99). *p < 0.05; **p < 0.001.

Table III. Descriptive information on GP care six months before and six months after psychological treatment of patients whose GAF scores clearly improved and those whose general functioning (GAF score) improved less, was stable, or worsened.

	Six months before psychological treatment	Six months after psychological treatment
GP care
Patients who improved by 20 points or more (n = 220, 46.9%)^1
Number of contacts, total (mean, SD, range)	5.8 (5.3) 0–33	4.5 (4.6) 0–26
Patients who improved less, were stable or worsened (n = 248, 53.1%)^1
Number of contacts, total (mean, SD, range)	6.4 (6.3) 0–32	5.2 (6.4) 0–40
Difference between groups (t-tests with equal variance)	p = 0.124	p = 0.099

Note: ¹The number of patients with complete data on GP care and GAF scores was 468.